MP MATERIALS CORP. / DE, 10-K filed on 2/28/2024
Annual Report
v3.24.0.1
COVER - USD ($)
$ in Billions
 12 Months Ended
Dec. 31, 2023
Feb. 20, 2024
Jun. 30, 2023
Cover [Abstract]      
Document Type 10-K    
Document Annual Report true    
Document Period End Date Dec. 31, 2023    
Current Fiscal Year End Date --12-31    
Document Transition Report false    
Entity File Number 001-39277    
Entity Registrant Name MP Materials Corp. / DE    
Entity Incorporation, State or Country Code DE    
Entity Tax Identification Number 84-4465489    
Entity Address, Address Line One 1700 S. Pavilion Center Drive, Suite 800    
Entity Address, City or Town Las Vegas    
Entity Address, State or Province NV    
Entity Address, Postal Zip Code 89135    
City Area Code 702    
Local Phone Number 844-6111    
Title of 12(b) Security Common Stock, par value of $0.0001 per share    
Trading Symbol MP    
Security Exchange Name NYSE    
Entity Well-known Seasoned Issuer No    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Interactive Data Current Yes    
Entity Filer Category Large Accelerated Filer    
Entity Small Business false    
Entity Emerging Growth Company false    
ICFR Auditor Attestation Flag true    
Entity Shell Company false    
Entity Public Float     $ 3.6
Entity Common Stock, Shares Outstanding   178,077,678  
Documents Incorporated by Reference Portions of the registrant’s definitive 2024 proxy statement, anticipated to be filed with the Securities and Exchange Commission within 120 days after the end of the registrant’s fiscal year, are incorporated by reference into Part III of this Form 10-K.    
Amendment Flag false    
Entity Central Index Key 0001801368    
Document Fiscal Year Focus 2023    
Document Fiscal Period Focus FY    
Document Financial Statement Error Correction false    
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AUDIT INFORMATION
 12 Months Ended
Dec. 31, 2023
Audit Information [Abstract]  
Auditor Name KPMG LLP
Auditor Location Denver, CO
Auditor Firm ID 185
v3.24.0.1
CONSOLIDATED BALANCE SHEETS - USD ($)
$ in Thousands
Dec. 31, 2023
Dec. 31, 2022
Current assets    
Cash and cash equivalents $ 263,351 $ 136,627
Short-term investments 734,493 1,045,718
Total cash, cash equivalents and short-term investments 997,844 1,182,345
Accounts receivable, net of allowance for credit losses of $0 and $0, respectively (including related party) 10,029 32,856
Inventories 95,182 57,554
Government grant receivable 19,302 0
Prepaid expenses and other current assets 8,820 21,073
Total current assets 1,131,177 1,293,828
Non-current assets    
Property, plant and equipment, net 1,158,054 935,743
Operating lease right-of-use assets 10,065 99
Inventories 13,350 5,744
Equity method investment 9,673 0
Intangible assets, net 8,881 89
Other non-current assets 5,252 2,284
Total non-current assets 1,205,275 943,959
Total assets 2,336,452 2,237,787
Current liabilities    
Accounts and construction payable 27,995 15,326
Accrued liabilities 73,939 56,939
Income taxes payable 0 21,163
Other current liabilities 6,616 4,053
Total current liabilities 108,550 97,481
Non-current liabilities    
Asset retirement obligations 5,518 5,295
Environmental obligations 16,545 16,580
Long-term debt, net 681,980 678,444
Operating lease liabilities 6,829 15
Deferred government grant 17,433 0
Deferred income taxes 130,793 122,353
Other non-current liabilities 3,025 4,985
Total non-current liabilities 862,123 827,672
Total liabilities 970,673 925,153
Commitments and contingencies (Note 13)
Stockholders’ equity:    
Preferred stock ($0.0001 par value, 50,000,000 shares authorized, none issued and outstanding in either year) 0 0
Common stock ($0.0001 par value, 450,000,000 shares authorized, 178,082,383 and 177,706,608 shares issued and outstanding, as of December 31, 2023 and December 31, 2022, respectively) 17 18
Additional paid-in capital 979,891 951,008
Retained earnings 385,726 361,419
Accumulated other comprehensive income 145 189
Total stockholders’ equity 1,365,779 1,312,634
Total liabilities and stockholders’ equity $ 2,336,452 $ 2,237,787
v3.24.0.1
CONSOLIDATED BALANCE SHEETS (PARENTHETICAL) - USD ($)
Dec. 31, 2023
Dec. 31, 2022
Statement of Financial Position [Abstract]    
Allowance for credit losses $ 0 $ 0
Preferred stock, par value (usd per share) $ 0.0001 $ 0.0001
Preferred stock, authorized (shares) 50,000,000 50,000,000
Preferred stock, issued (shares) 0 0
Preferred shares, outstanding (shares) 0 0
Common stock, par value (usd per share) $ 0.0001 $ 0.0001
Common stock, authorized (shares) 450,000,000 450,000,000
Common stock, issued (shares) 178,082,383 177,706,608
Common stock, outstanding (shares) 178,082,383 177,706,608
v3.24.0.1
CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Total revenue $ 253,445 $ 527,510 $ 331,952
Operating costs and expenses:      
Cost of sales (excluding depreciation, depletion and amortization) (including related party) 92,714 92,218 76,253
Selling, general and administrative 79,245 75,857 56,646
Depreciation, depletion and amortization 55,709 18,356 24,382
Start-up costs 21,330 7,551 378
Advanced projects and development 14,932 4,249 4,195
Other operating costs and expenses 7,234 1,868 4,753
Total operating costs and expenses 271,164 200,099 166,607
Operating income (loss) (17,719) 327,411 165,345
Interest expense, net (5,254) (5,786) (8,904)
Other income, net 56,048 19,527 3,754
Income before income taxes 33,075 341,152 160,195
Income tax expense (8,768) (52,148) (25,158)
Net income $ 24,307 $ 289,004 $ 135,037
Earnings per share:      
Basic (in USD per share) $ 0.14 $ 1.64 $ 0.78
Diluted (in USD per share) $ 0.14 $ 1.52 $ 0.73
Weighted-average shares outstanding:      
Basic (in shares) 177,181,661 176,519,203 173,469,546
Diluted (in shares) 178,152,212 193,453,087 189,844,028
Rare earth concentrate (including related party)      
Total revenue $ 252,468 $ 517,267 $ 328,563
NdPr oxide and metal      
Total revenue 695 0 0
Other rare earth products (including related party)      
Total revenue $ 282 $ 10,243 $ 3,389
v3.24.0.1
CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Statement of Comprehensive Income [Abstract]      
Net income $ 24,307 $ 289,004 $ 135,037
Other comprehensive income (loss), net of tax:      
Change in net unrealized gains (losses) on available-for-sale securities (44) 189 0
Total comprehensive income $ 24,263 $ 289,193 $ 135,037
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CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS’ EQUITY (DEFICIT) - USD ($)
$ in Thousands
Total
Preferred Stock
Common Stock
Additional Paid-in Capital
Retained Earnings (Accumulated Deficit)
Accumulated Other Comprehensive Income
Beginning balance (shares) at Dec. 31, 2020   0 170,719,979      
Beginning balance at Dec. 31, 2020 $ 853,877 $ 0 $ 17 $ 916,482 $ (62,622) $ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]            
Redemption of Public Warrants (in shares)     7,080,005      
Redemption of Public Warrants (1)   $ 1 (2)    
Stock-based compensation (shares)     180,026      
Stock-based compensation 22,931     22,931    
Forfeiture of restricted stock (in shares)     90,000      
Shares used to settle payroll tax withholding (shares)     (73,456)      
Shares used to settle payroll tax withholding (3,330)     (3,330)    
Net income 135,037       135,037  
Unrealized gains (losses) on available-for-sale securities 0          
Other 218     218    
Ending balance (shares) at Dec. 31, 2021   0 177,816,554      
Ending balance at Dec. 31, 2021 1,008,732 $ 0 $ 18 936,299 72,415 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]            
Stock-based compensation (shares)     357,845      
Stock-based compensation 33,066     33,066    
Forfeiture of restricted stock 0          
Shares used to settle payroll tax withholding (shares)     (467,791)      
Shares used to settle payroll tax withholding (18,357)     (18,357)    
Net income 289,004       289,004  
Unrealized gains (losses) on available-for-sale securities 189         189
Ending balance (shares) at Dec. 31, 2022   0 177,706,608      
Ending balance at Dec. 31, 2022 1,312,634 $ 0 $ 18 951,008 361,419 189
Increase (Decrease) in Stockholders' Equity [Roll Forward]            
Stock-based compensation (shares)     472,047      
Stock-based compensation 27,104     27,104    
Shares used to settle payroll tax withholding (shares)     (248,776)      
Shares used to settle payroll tax withholding (7,185)   $ (1) (7,184)    
Common stock issued to acquire intangible assets (in shares)     (152,504)      
Common stock issued to acquire intangible asset 8,963     (8,963)    
Net income 24,307       24,307  
Unrealized gains (losses) on available-for-sale securities (44)         (44)
Ending balance (shares) at Dec. 31, 2023   0 178,082,383      
Ending balance at Dec. 31, 2023 $ 1,365,779 $ 0 $ 17 $ 979,891 $ 385,726 $ 145
v3.24.0.1
CONSOLIDATED STATEMENTS OF CASH FLOWS
$ in Thousands
 12 Months Ended
Dec. 31, 2023
USD ($)
Dec. 31, 2022
USD ($)
Dec. 31, 2021
USD ($)
Operating activities:      
Net income $ 24,307 $ 289,004 $ 135,037
Adjustments to reconcile net income to net cash provided by operating activities:      
Depreciation, depletion and amortization 55,709 18,356 24,382
Accretion of asset retirement and environmental obligations 908 1,477 2,375
Accretion of discount on short-term investments (26,316) (9,958) 0
Gain on forgiveness of Paycheck Protection Loan 0 0 (3,401)
Loss on disposals of long-lived assets, net 808 391 569
Stock-based compensation expense 25,236 31,780 22,931
Accretion of debt discount and amortization of debt issuance costs 3,536 4,034 7,384
Write-downs of inventories 2,285 0 1,809
Revenue recognized in exchange for debt principal reduction 0 (13,566) (54,828)
Deferred income taxes 8,455 17,789 17,425
Decrease (increase) in operating assets:      
Accounts receivable (including related party) 22,827 18,153 (47,420)
Inventories (47,099) (24,314) (8,229)
Government grant receivable (19,302) 0 0
Prepaid expenses, other current and non-current assets 2,377 (8,223) (4,154)
Increase (decrease) in operating liabilities:      
Accounts payable and accrued liabilities 11,305 1,962 5,530
Income taxes payable (21,163) 17,700 3,463
Deferred government grant 19,120 0 0
Other current and non-current liabilities (294) (1,071) (902)
Net cash provided by operating activities 62,699 343,514 101,971
Investing activities:      
Additions to property, plant and equipment (261,897) (326,595) (123,870)
Purchases of short-term investments (1,185,477) (2,779,666) 0
Proceeds from sales of short-term investments 507,736 1,463,160 0
Proceeds from maturities of short-term investments 1,015,190 281,000 0
Investment in equity method investee (9,673) 0 0
Proceeds from sale of property, plant and equipment 18 0 125
Proceeds from government awards used for construction 2,800 5,130 4,382
Net cash provided by (used in) investing activities 68,697 (1,356,971) (119,363)
Financing activities:      
Proceeds from issuance of long-term debt 0 0 690,000
Principal payments on debt obligations and finance leases (2,732) (5,834) (2,435)
Payment of debt issuance costs 0 0 (17,749)
Tax withholding on stock-based awards (7,185) (18,357) (3,330)
Other 0 0 (377)
Net cash provided by (used in) financing activities (9,917) (24,191) 666,109
Net change in cash, cash equivalents and restricted cash 121,479 (1,037,648) 648,717
Cash, cash equivalents and restricted cash beginning balance 143,509 1,181,157 532,440
Cash, cash equivalents and restricted cash ending balance 264,988 143,509 1,181,157
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]      
Cash and cash equivalents 263,351 136,627 1,179,297
Restricted cash, current 1,290 6,287 1,344
Restricted cash, non-current 347 595 516
Total cash, cash equivalents and restricted cash $ 264,988 $ 143,509 $ 1,181,157
v3.24.0.1
DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION
 12 Months Ended
Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]  
DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION
Description of Business: MP Materials Corp., including its subsidiaries (the “Company” or “MP Materials”), is the largest producer of rare earth materials in the Western Hemisphere. The Company, which is headquartered in Las Vegas, Nevada, owns and operates the Mountain Pass Rare Earth Mine and Processing Facility (“Mountain Pass”), the only rare earth mining and processing site of scale in North America, and is constructing a rare earth metal, alloy and magnet manufacturing facility in Fort Worth, Texas (the “Fort Worth Facility”), where the Company anticipates manufacturing neodymium-iron-boron (“NdFeB”) permanent magnets and its precursor products.
The Company produces rare earth concentrate products as well as refined rare earth oxides and related products. The rare earth concentrate is principally sold pursuant to the Offtake Agreement to Shenghe (as such terms are defined in Note 20, “Related-Party Transactions”), a related party of the Company, that, in turn, typically sells that product to refiners in China. Following the commissioning of the Company’s Stage II optimization project (“Stage II”) in the third quarter of 2023, the Company began producing separated rare earth products, including neodymium-praseodymium (“NdPr”) oxide, that it began selling to customers globally in the fourth quarter of 2023. Additionally, in April 2022, the Company entered into a long-term agreement with General Motors Company (NYSE: GM) (“GM”) to supply U.S.-sourced and manufactured rare earth materials and finished magnets for the electric motors in more than a dozen models based on GM’s Ultium Platform. These developments are part of the Company’s Stage III downstream expansion strategy (“Stage III”).
Operating segments are defined as components of an enterprise engaged in business activities, about which separate financial information is available and evaluated regularly by the chief operating decision maker (“CODM”), or decision-making group, in deciding how to allocate resources and in assessing performance. The Company’s CODM views the Company’s operations and manages the business as one reportable segment.
The cash flows and profitability of the Company’s operations are significantly affected by the market price of rare earth products. The prices of rare earth products are affected by numerous factors beyond the Company’s control. The products of the Company are sold globally, with a primary focus in the Asian market due to the refining, metallization, and magnet manufacturing capabilities of the region. Rare earth products are critical inputs in hundreds of existing and emerging clean-tech applications including electric vehicles and wind turbines as well as robotics, drones, and defense applications.
Basis of Presentation: The Consolidated Financial Statements of the Company have been prepared in accordance with generally accepted accounting principles in the U.S. (“GAAP”) and with the rules and regulations of the U.S. Securities and Exchange Commission (the “SEC”).
v3.24.0.1
SIGNIFICANT ACCOUNTING POLICIES
 12 Months Ended
Dec. 31, 2023
Accounting Policies [Abstract]  
SIGNIFICANT ACCOUNTING POLICIES SIGNIFICANT ACCOUNTING POLICIES
Principles of Consolidation: The Consolidated Financial Statements include the accounts of MP Materials Corp. and its subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation.
Concentration of Risk: Financial instruments that potentially subject the Company to credit risk consist principally of cash, cash equivalents and short-term investments, and receivables from customers. The Company believes that its credit risk is limited because the Company’s current contracts are with companies that have a reliable payment history. The Company does not believe that it is exposed to any significant risks related to its cash accounts, money market funds, or short-term investments.
As of December 31, 2023, Shenghe was the Company’s principal customer and accounted for more than 90% of revenue. Rare earth concentrate is not quoted on any major commodities market or exchange and demand for rare earth concentrate is currently constrained to a relatively limited number of refiners, a significant majority of which are based in China. Uncertainty exists as to the market price of rare earth oxide (“REO”), as evidenced by the volatility experienced in 2022 and 2023 primarily due to concerns over the global economic conditions and actual or perceived concerns over increases in the supply of or slower growth in the demand for rare earth products. Furthermore, while revenue is generated in the U.S., Shenghe conducts its primary operations in China and may transport and sell products in the Chinese market. Therefore, the Company’s revenue is affected by Shenghe’s ultimate realized prices in China, including the impact of changes in the exchange rate between the Chinese Yuan and the U.S. dollar. In addition, the ongoing economic conflict between China and the U.S., which has previously resulted in tariffs and trade barriers, may negatively affect the Company’s business and results of operations. See Note 20, “Related-Party Transactions,” for additional information.
Use of Estimates: The preparation of the Consolidated Financial Statements in conformity with GAAP requires management to make estimates and assumptions that affect (i) the reported amounts of assets and liabilities, (ii) the disclosure of contingent assets and liabilities at the date of the Consolidated Financial Statements, and (iii) the reported amounts of revenues and expenses during the reporting period. The more significant areas requiring the use of management estimates and assumptions relate to the useful lives and recoverability of long-lived assets (such as the effects of mineral reserves and cash flows from operating the mine in determining the life of the mine); the valuation allowance of deferred tax assets; asset retirement and environmental obligations; and determining the net realizable value of inventories. Management bases its estimates on historical experience and on various other assumptions that are believed to be reasonable under the circumstances. Accordingly, actual results may differ from those estimates.
Cash, Cash Equivalents and Investments: Cash and cash equivalents consist of all cash balances and highly liquid investments, including commercial paper, certificates of deposit, and U.S. treasury and agency securities, with a maturity of three months or less at the time of purchase.
The Company’s investments in U.S. treasury and agency securities, commercial paper, and certificates of deposit have been classified and accounted for as available-for-sale securities and the Company reevaluates the classification each reporting period. The Company classifies its available-for-sale securities that do not otherwise meet the requirements to be accounted for as cash equivalents as either current or non-current based on each instrument’s underlying contractual maturity date as well as the Company’s expectations of sales and redemptions within the next twelve months. See Note 3, “Cash, Cash Equivalents and Investments,” for additional information.
Available-for-sale securities are recorded at fair value each reporting period. For unrealized losses in securities that the Company intends to hold and will not more likely than not be required to sell before recovery, the Company further evaluates whether declines in fair value below amortized cost are due to credit or non-credit related factors. The Company considers credit related impairments to be changes in value that are driven by a change in the creditor’s ability to meet its payment obligations and records an allowance and recognizes a corresponding loss when the impairment is incurred.
Unrealized non-credit related losses and unrealized gains are reported, net of income taxes, in “Accumulated other comprehensive income” within the Company’s Consolidated Balance Sheets, until realized. Realized gains and losses are determined based on the specific identification method and are reported in “Other income, net” within the Company’s Consolidated Statements of Operations upon realization. Premiums and discounts are amortized or accreted over the life of the related available-for-sale security as an adjustment to yield using the straight-line method. Interest income is recognized when earned. These amounts are reported in “Other income, net” within the Company’s Consolidated Statements of Operations. Accrued interest receivable was $0.9 million and $2.5 million as of December 31, 2023 and 2022, respectively, and is included in “Prepaid expenses and other current assets” within the Company’s Consolidated Balance Sheets.
Restricted Cash: Restricted cash consists of funds that are contractually restricted as to usage or withdrawal due to legal agreement. The Company determines current or non-current classification based on the expected duration of the restriction. Current and non-current restricted cash is included in “Prepaid expenses and other current assets” and “Other non-current assets,” respectively, within the Consolidated Balance Sheets.
Accounts Receivable: Accounts receivable pertain to receivables arising from contracts with customers and are recorded at the invoiced amount and do not bear interest. The Company evaluates its estimate of expected credit losses based on historical experience and current economic conditions for each portfolio of customers, though at present, the amounts are typically concentrated in a single customer. As of December 31, 2023 and 2022, the Company did not have an allowance for expected credit losses, as principally all of the Company’s receivables are from Shenghe and there is no history or expectation of uncollectible amounts.
Inventories: Inventories consist of raw materials, supplies, mined ore stockpiles, work in process, and finished goods. Raw materials and supplies consist of spare parts, reagent chemicals, maintenance supplies, and packaging materials used in the production of rare earth products. Mined ore stockpiles represent bastnaesite ore that has been mined and stockpiled for future processing. Work in process consists of bastnaesite ore and separated rare earth products in various stages of the production process, as well as finished and packaged NdPr oxide shipped to tollers for processing into NdPr metal. Finished goods primarily consists of packaged traditional or roasted bastnaesite concentrate as well as finished and packaged NdPr oxide and NdPr metal (including quantities tolled) that is ready for sale.
Raw materials, mined ore stockpiles, work in process, and finished goods are carried at average cost. Supplies are carried at moving average cost. All inventories are carried at the lower of cost or net realizable value, which represents the estimated selling price of the product during the ordinary course of business based on current market conditions less reasonably predictable costs of completion, disposal, and transportation. Inventory cost includes all costs directly attributable to the
manufacturing process, including labor and stripping costs, and an appropriate portion of production overhead costs, including depreciation, based on normal capacity of the production facilities.
Stockpiled ore tonnages are verified by periodic surveys. The Company evaluates the carrying amount of inventory each reporting period, considering recent market prices, slow-moving items, obsolescence, excess inventory levels, and other factors and recognizes related write-downs if it is determined that the inventory is impaired. Mined ore stockpiles that are not expected to be processed within the next twelve months and raw materials and spare parts that are not expected to be consumed within the next twelve months are classified as non-current. See also Note 4, “Inventories.”
Property, Plant and Equipment: Property, plant and equipment are recorded at cost and depreciated over their useful lives. Expenditures for new property, plant and equipment and improvements that extend the useful life or functionality of the assets are recorded at their cost of acquisition or construction. Depreciation on property, plant and equipment is recognized on a straight-line basis over their estimated useful lives, as follows:
Years
Land improvements
10-25
Buildings and building improvements
10-40
Machinery and equipment
3-20
Assets under construction include costs directly attributable to the construction or development of long-lived assets. These costs may include labor and employee benefits associated with the construction of the asset, site preparation, permitting, engineering and design, installation and assembly, procurement, insurance, legal, initial commissioning, and interest on borrowings to finance the construction of the assets. Depreciation is not recorded on the related assets until they are ready for their intended use. Repair and maintenance costs that do not extend the useful life of an asset are expensed as incurred. Gains and losses arising from the sale or disposal of property, plant and equipment are determined as the difference between the proceeds from sale or disposal and the carrying amount of the asset, and are included, along with demolition costs, in “Other operating costs and expenses” within the Company’s Consolidated Statements of Operations.
Property, plant and equipment primarily relate to the Company’s open-pit mine and processing and separations facility at Mountain Pass as well as the building associated with the Company’s Fort Worth Facility. In addition to the mine pit, Mountain Pass includes a crusher and mill/flotation plant, mineral recovery and separation plants, tailings processing and storage facilities, product finishing facilities, on-site evaporation ponds, a combined heat and power plant, water treatment plant, a chlor-alkali plant, as well as laboratory facilities to support research and development activities, offices, warehouses and support infrastructure. See also Note 5, “Property, Plant and Equipment.”
Mineral Rights: The Company capitalizes costs for acquiring and leasing mining properties and expenses costs to maintain mineral rights as incurred. Depletion on mineral rights is recognized on a straight-line basis over the estimated remaining useful life of the mine, which was approximately 33 years as of December 31, 2023. The Company determined that the straight-line method of depletion appropriately captures the estimated economic costs of extracting the minerals of the mine across its estimated useful life, and aligns with the benefit obtained from the depletion of the asset consistent with the current mine plan. Mineral rights are classified as a component of “Property, plant and equipment” within the Company’s Consolidated Balance Sheets. See also Note 5, “Property, Plant and Equipment.”
Leases: The Company determines if an arrangement is, or contains, a lease at contract inception. In some cases, the Company has determined that its lease arrangements include both lease and non-lease components. The Company has elected to use a practical expedient to account for each separate lease component and its associated non-lease components as a single lease component for the majority of its asset classes. The Company recognizes right-of-use (“ROU”) assets and lease liabilities upon commencement for all leases with a lease term greater than 12 months. The Company has elected to use a practical expedient to not recognize leases with a lease term of 12 months or less in the Consolidated Balance Sheets for the majority of its asset classes. These short-term leases are expensed on a straight-line basis over the lease term.
ROU assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent the Company’s obligation to make lease payments arising from the lease. ROU assets and lease liabilities are recognized at commencement date of the lease based on the present value of lease payments over the lease term. When the rate implicit in the lease cannot be readily determined, the Company utilizes its incremental borrowing rate in determining the present value of the future lease payments. Lease liabilities are accreted each period and reduced for payments. The ROU asset also includes other adjustments, such as for the effects of lease prepayments, initial lease costs, or lease incentives received. The lease term may include periods covered by options to extend or terminate the lease when it is either reasonably certain that the Company will
exercise a renewal option, or reasonably certain it will not exercise an early termination option. For operating leases, lease expense is recognized on a straight-line basis over the lease term. For finance leases, the ROU asset amortizes on a straight-line basis over the shorter of the lease term or the useful life of the underlying asset (or the useful life of the underlying asset if title transfers at the end of the lease term or there is a purchase option the Company is reasonably certain to exercise) and the lease liability accretes interest based on the interest method using the discount rate determined at lease commencement. For operating and finance leases, variable lease payments not included in the lease liability are expensed as incurred unless such costs are capitalized as part of another asset (e.g., inventory). Additionally, ROU assets are subject to impairment testing whenever events or changes in circumstances indicate that their carrying amount may not be recoverable. If the carrying amounts of ROU assets exceed their fair value, the excess amount is recognized as an impairment. See also Note 11, “Leases.”
Impairment of Long-Lived Assets: Long-lived assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset or asset group may not be recoverable. In estimating undiscounted cash flows, assets are grouped at the lowest level for which there are identifiable cash flows that are largely independent of undiscounted cash flows from other asset groups. The Company’s estimates of undiscounted cash flows are based on numerous assumptions, and it is possible that actual cash flows may differ significantly from estimates, as actual produced reserves, prices, commodity-based and other costs, and closure costs are each subject to significant risks and uncertainties. The estimated undiscounted cash flows used to assess recoverability of long-lived assets and to measure the fair value of the Company’s mining operations are derived from current business plans, which are developed using short-term price forecasts reflective of the current price environment and the Company’s projections for long-term average prices. In addition to short- and long-term price assumptions, other assumptions include estimates of production costs; proven and probable mineral reserve estimates, including the timing and cost to develop and produce the reserves; value beyond proven and probable estimates; and estimated future closure costs.
If the carrying amount of the long-lived asset or asset groups is not recoverable on an undiscounted cash flows basis, an impairment is recognized to the extent that the carrying amount exceeds its fair value. Fair value is determined through various valuation techniques, including discounted cash flow models, quoted market values, and third-party independent appraisals, based on the approach the Company believes a market participant would use.
Equity Method Investment: Investments in equity securities are accounted for under the equity method if the Company has the ability to exercise significant influence, but not control, over an investee’s operating and financial policies. Judgment regarding the level of influence includes considering key factors such as the Company’s ownership interest, representation on the board of directors, participation in policy-making decisions and material intra-entity transactions. Under the equity method, an investment’s carrying amount is adjusted for the Company’s share of the investee’s net income or loss (including other comprehensive income or loss), amortization/accretion of certain basis differences (if any), capital contributions to and distributions from an investee, as well as any other-than-temporary impairments.
The Company records its share of an equity method investment’s net income or loss on a one-quarter lag due to the timing of when an investee’s financial statements become available. The Company evaluates material events occurring during the one-quarter lag to determine whether the effects of such events should be reflected or disclosed within the Company’s Consolidated Financial Statements. For intra-entity transactions between the Company and its equity method investee, the Company eliminates its share of profits and losses until realized by the Company or investee. Such elimination is recorded as an adjustment of the carrying amount of the equity method investment.
The Company evaluates its equity method investment for impairment whenever events or changes in circumstances indicate that the carrying amount of its investment may not be recoverable. If such conditions exist, the Company compares the estimated fair value of the investment to its carrying amount to determine if an impairment is indicated, and if so, determines whether the impairment is “other-than-temporary” based on its assessment of all relevant factors, including consideration of the Company’s intent and ability to retain its investment. If the Company determines the decline is other-than-temporary, an impairment is recognized for the excess amount by which the investment’s carrying amount exceeds its fair value. See Note 6, “Equity Method Investment,” for additional information.
Intangible Assets: Indefinite-lived intangible assets are tested annually for impairment, or more frequently if events or changes in circumstances indicate that it is more likely than not that the assets are impaired. If the carrying amounts of the indefinite-lived intangible assets exceed their fair value, the excess amount is recognized as an impairment. Intangible assets that have a definite life are amortized on a straight-line basis over their estimated useful lives to reflect the expected pattern of economic benefits consumed. The Company reviews the carrying amount of its amortizing intangible assets for possible impairment whenever events or changes in circumstances indicate that their carrying amount may not be recoverable. If the carrying amounts of the amortizing intangible assets exceed their fair value, the excess amount is recognized as an impairment. Once an impairment of an intangible asset has been recorded, it cannot be reversed. See also Note 7, “Intangible Assets.”
Asset Retirement Obligations: The Company recognizes asset retirement obligations (“ARO”) for estimated costs of legally and contractually required closure, dismantlement, and reclamation activities associated with Mountain Pass. ARO are initially recognized at their estimated fair value in the period in which the obligation originates. Fair value is based on the expected timing of reclamation activities, cash flows to perform activities, amount and uncertainty associated with the cash flows, including adjustments for a market risk premium, and discounted using a credit-adjusted risk-free rate. The liability is accreted over time through periodic charges to earnings and reduced as reclamation activities occur with differences between estimated and actual amounts recognized as an adjustment to operating expenses. Accretion of asset retirement obligations is included in “Other operating costs and expenses” within the Company’s Consolidated Statements of Operations.
Subsequent increments in expected undiscounted cash flows are measured at their discounted values using updated estimates of the Company’s credit-adjusted risk-free rate applied to the increment only. Subsequent decrements in expected undiscounted cash flows are reduced based on the weighted-average credit-adjusted risk-free rate associated with the obligation. When increments and decrements are caused by a change in the estimated timing of settlement, the Company treats the increase in cash flows in the year of the updated estimate as an increment and the increase in cash flows in the original year as a decrement. Associated asset retirement costs, including the effect of increments and decrements, are recognized as adjustments to the related asset’s carrying amount and depreciated over the related asset’s remaining useful life. If a decrement is greater than the carrying amount of the related asset, the difference is recognized as a reduction to depreciation expense. See also Note 8, “Asset Retirement and Environmental Obligations.”
Environmental Obligations: The Company has certain environmental remediation obligations that primarily relate to groundwater monitoring activities. Estimated remediation costs are accrued based on management’s best estimate at the end of each reporting period of the costs expected to be incurred to settle the obligation when those amounts are probable and estimable. Such cost estimates may include ongoing care, maintenance and monitoring costs associated with remediation activities. Changes in remediation estimates are reflected in earnings in the period the estimate is revised. Remediation costs included in environmental obligations are discounted to their present value when payments are readily estimable, and are discounted using a risk-free rate, which the Company derives from U.S. Treasury yields. Accretion of environmental obligations is included in “Other operating costs and expenses” within the Company’s Consolidated Statements of Operations. See also Note 8, “Asset Retirement and Environmental Obligations.”
Debt Issuance Costs: Costs that are incurred by the Company in connection with the issuance of debt are deferred and amortized to interest expense using the effective interest method over the contractual term of the underlying indebtedness. Debt issuance costs reduce the carrying amount of the associated debt. See also, Note 10, “Debt Obligations.”
Commitments and Contingencies: Liabilities for loss contingencies arising from claims, assessments, litigation, fines and penalties, and other sources are recorded when it is probable that a liability has been incurred and the amount can be reasonably estimated. If a loss contingency is not probable or reasonably estimable, disclosure of the contingency and estimated range of loss, if determinable, is made in the financial statements when it is at least reasonably possible that a material loss could be incurred. Legal costs incurred in connection with loss contingencies are expensed as incurred. See also Note 13, “Commitments and Contingencies.”
Revenue Recognition: The Company’s revenue comes from sales of rare earth products produced at Mountain Pass. The Company’s sales are primarily to an affiliate of Shenghe. The Company’s performance obligation is to produce and deliver rare earth products and the Company recognizes revenue at the point in time control of the products transfers to the customer, which is typically when the rare earth products are delivered to the agreed-upon shipping point. At that time, the customer has the ability to direct the use of and obtain substantially all of the remaining benefits from the products, and the customer bears the risk of loss. Commissions paid to distributors are deemed to be consideration payable to customers and are recorded as a reduction of the transaction prices.
For sales to unrelated third parties, the transaction price is agreed to at the time the sale is entered into. For sales to Shenghe, the transaction price is based on a preliminary market price (net of taxes, tariffs, and certain other agreed charges) less applicable discounts per metric ton (“MT”), subject to an adjustment for the ultimate market price of the product realized by Shenghe upon sales to their customers. Consequently, the ultimate market prices are a form of variable consideration. Initial pricing is typically billed upon delivering the product to the agreed-upon shipping point and paid within 30 days or less. Final adjustments to prices may take longer to resolve. When the final price has not been resolved by the end of a reporting period, the Company estimates the expected sales price based on the initial price, current market pricing and known quality measurements, and further constrains such amounts to an amount that is probable not to result in a significant reversal of previously-recognized revenue. Revenue from product sales is recorded net of taxes collected from customers that are remitted to governmental authorities. When necessary and appropriate, the Company applies a portfolio approach in estimating a refund obligation. See also Note 15, “Revenue Recognition.”
Government Grants: Government grants represent benefits provided by federal, state, or local governments that are not subject to the scope of Accounting Standards Codification (“ASC”) Topic 740, “Income Taxes” (“ASC 740”). Government grants are recognized when there is reasonable assurance the conditions of the grant will be met, and the grant will be received. When a grant is related to the purchase or construction of a long-lived asset (considered asset-based grants), the funds received are recorded as reductions of the related asset’s carrying amount, thereby reducing future depreciation expense. Alternatively, when a grant is related to an expense item (considered income-based grants), it is recognized as a reduction of expense to which the grant activity relates over the periods necessary to match the grant on a systematic basis to the costs that it is intended to compensate. See also Note 16, “Government Grants.”
Stock-Based Compensation: The cost of employee services received in exchange for an award of equity instruments is based on the grant-date fair value of the award. The fair value of Stock Awards (as defined in Note 17, “Stock-based Compensation”) is equal to the fair value of the Company’s stock on the grant date. The fair value of performance awards that include performance and/or market conditions is determined using a Monte Carlo simulation technique. The Monte Carlo simulation requires the use of inputs and assumptions such as the grant-date closing stock price, expected volatility, correlation coefficient to relevant peer groups or indices, risk-free interest rate and dividend yield.
Compensation cost for Stock Awards with graded vesting schedules is recognized on a straight-line basis over the requisite service period for each separately vesting portion of the award as if the award was, in substance, multiple awards, which results in accelerated recognition of compensation cost. Compensation cost for performance awards with cliff vesting schedules is recognized on a straight-line basis over the requisite service period. Compensation cost is not adjusted based on the actual achievement of the market-based performance goals. The Company accounts for forfeitures in the period in which they occur based on actual forfeitures. See also Note 17, “Stock-based Compensation.”
Start-up Costs: Costs associated with restarting an existing facility or commissioning a new facility, circuit or process of the Company’s production, manufacturing, or separations facilities prior to the achievement of commercial production, that do not qualify for capitalization, are expensed as incurred and considered start-up costs. Such costs may include certain salaries and wages, outside services, parts, training, and utilities, among other items, used or consumed directly in these start-up activities.
Earnings Per Share: Basic earnings per share (“EPS”) is computed by dividing net income by the weighted-average number of common shares outstanding during the period. Diluted EPS reflects the additional dilution for all potentially dilutive securities such as unvested Stock Awards. See also Note 19, “Earnings per Share.”
Income Taxes: The Company accounts for income taxes using the balance sheet method, recognizing certain temporary differences between the book basis of the liabilities and assets and the related income tax basis for such liabilities and assets. This method generates either a net deferred income tax liability or asset for the Company, as measured by the statutory tax rates in effect. The Company derives a deferred income tax expense or benefit by recording the change in either the net deferred income tax liability or asset balance for the year. The Company’s policy, if it were to have uncertain tax positions, is to recognize interest and/or penalties related to unrecognized tax benefits as part of its income tax expense. See also Note 12, “Income Taxes.”
Valuation of Deferred Tax Assets: The Company’s deferred income tax assets include certain future tax benefits. The Company records a valuation allowance against any portion of those deferred income tax assets when it believes, based on the weight of available evidence, it is more likely than not that some portion or all of the deferred income tax asset will not be realized. The Company reviews the likelihood that the benefit of the deferred tax assets will be realized and the need for valuation allowances on a quarterly basis, or more frequently if events indicate that a review is required.
Certain categories of evidence carry more weight in the analysis than others based upon the extent to which the evidence may be objectively verified. The Company looks to the nature and severity of cumulative pretax losses (if any) in the current three-year period ending on the evaluation date, recent pretax losses and/or expectations of future pretax losses. Other factors considered in the determination of the probability of the realization of the deferred tax assets include, but are not limited to: earnings history; projected future financial and taxable income based upon existing reserves and long-term estimates of commodity prices; the duration of statutory carry forward periods; prudent and feasible tax planning strategies readily available that may alter the timing of reversal of the temporary difference; nature of temporary differences and predictability of reversal patterns of existing temporary differences; and the sensitivity of future forecasted results to commodity prices and other factors.
Concluding that a valuation allowance is not required is difficult when there is significant negative evidence which is objective and verifiable, such as cumulative losses in recent years. However, recent cumulative losses are not solely determinative of the need for a valuation allowance. The Company also considers all other available positive and negative evidence in its analysis. See also Note 12, “Income Taxes.”
Recently Issued Accounting Pronouncements: During the year ended December 31, 2023, there were no accounting pronouncements adopted by the Company that had a material impact on the Company’s Consolidated Financial Statements.
In November 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2023-07, “Improvements to Reportable Segment Disclosures” (“ASU 2023-07”), which expands public entities’ segment disclosures by requiring disclosure of significant segment expenses that are regularly provided to the CODM and included within each reported measure of segment profit or loss, an amount and description of its composition for other segment items, and interim disclosures of a reportable segment’s profit or loss and assets. All disclosure requirements under ASU 2023-07 are also required for public entities with a single reportable segment. ASU 2023-07 is effective for the Company’s fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024, with early adoption permitted, and should be applied on a retrospective basis. The Company is currently evaluating the effect of adopting ASU 2023-07 on its disclosures.
In December 2023, the FASB issued ASU No. 2023-09, “Improvements to Income Tax Disclosures” (“ASU 2023-09”), which enhances public entities’ existing income tax disclosures to better assess how an entity’s operations, related tax risks, tax planning and operational opportunities affect its tax rate and prospects for future cash flows. ASU 2023-09 requires public entities to annually disclose specific categories in the rate reconciliation table of the income tax footnote and provide additional information for reconciling items that meet a quantitative threshold. ASU 2023-09 is effective for the Company’s annual periods beginning after December 15, 2024, with early adoption permitted. The Company is currently evaluating the effect of adopting ASU 2023-09 on its disclosures.
Reclassifications: Certain amounts in prior periods have been reclassified to conform to the current year presentation.
v3.24.0.1
CASH, CASH EQUIVALENTS AND INVESTMENTS
 12 Months Ended
Dec. 31, 2023
Investments, Debt and Equity Securities [Abstract]  
CASH, CASH EQUIVALENTS AND INVESTMENTS CASH, CASH EQUIVALENTS AND INVESTMENTS
The following table presents the Company’s cash, cash equivalents and short-term investments:
December 31, 2023December 31, 2022
(in thousands)Amortized Cost BasisUnrealized GainsUnrealized LossesEstimated Fair ValueAmortized Cost BasisUnrealized GainsUnrealized LossesEstimated Fair Value
Cash:
Demand deposits$2,795 $— $— $2,795 $7,373 $— $— $7,373 
Cash equivalents:
Money market funds61,166 — — 61,166 64,855 — — 64,855 
U.S. agency securities— — — — 63,605 1 (2)63,604 
U.S. Treasury securities92,113 14 — 92,127 795 — — 795 
Commercial paper
93,447 15 — 93,462 — — — — 
Certificates of deposit
13,799 2 — 13,801 — — — — 
Total cash equivalents260,525 31 — 260,556 129,255 1 (2)129,254 
Total cash and equivalents263,320 31 — 263,351 136,628 1 (2)136,627 
Short-term investments:
U.S. agency securities118,370 — (78)118,292 979,878 361 (17)980,222 
U.S. Treasury securities615,962 249 (10)616,201 65,586 1 (91)65,496 
Total short-term investments734,332 249 (88)734,493 1,045,464 362 (108)1,045,718 
Total cash, cash equivalents and short-term investments$997,652 $280 $(88)$997,844 $1,182,092 $363 $(110)$1,182,345 
The Company does not intend to sell, nor is it more likely than not that the Company will be required to sell, any investments in unrealized loss positions before recovery of their amortized cost basis. The Company did not recognize any credit losses related to its available-for-sale investments during the years ended December 31, 2023 and 2022. The unrealized losses on the Company’s available-for-sale investments were primarily due to unfavorable changes in interest rates subsequent to initial purchase. None of the available-for-sale investments held as of December 31, 2023, were in a continuous unrealized loss position for greater than 12 months and the unrealized losses and the related risk of expected credit losses were not material.
The Company recognized the following income and expense amounts, all of which are included in “Other income, net” within the Company’s Consolidated Statements of Operations:
For the year ended December 31,
(in thousands)202320222021
Gross realized gains
$575 $258 $— 
Gross realized losses
$203 $573 $— 
Interest and investment income(1)
$55,637 $19,774 $— 
(1)Includes interest and investment income on the Company’s available-for-sale securities and other money market funds.
As of December 31, 2023, the fair values of available-for-sale investments, by remaining contractual maturity, were as follows:
(in thousands)
Due within one year$911,096 
Due after one year through two years22,787 
Total$933,883 
v3.24.0.1
INVENTORIES
 12 Months Ended
Dec. 31, 2023
Inventory Disclosure [Abstract]  
INVENTORIES INVENTORIES
The Company’s inventories consisted of the following:
December 31,
(in thousands)20232022
Raw materials and supplies, including spare parts(1)
$42,371 $28,590 
Mined ore stockpiles28,507 25,502 
Work in process
15,019 1,710 
Finished goods
9,285 1,752 
Total current inventories95,182 57,554 
Add: Non-current portion(2)
13,350 5,744 
Total inventories$108,532 $63,298 
(1)Includes raw materials to support activities pertaining to the Company’s rare earth metal, alloy and magnet manufacturing capabilities.
(2)Represents stockpiled ore that is not expected to be processed within the next 12 months as well as certain raw materials that are not expected to be consumed within the next 12 months. The stockpiled ore amounts as of December 31, 2023 and 2022, were $9.1 million and $5.7 million, respectively.
During the fourth quarter of 2023, the Company determined that the cost of a portion of its inventory exceeded its net realizable value, resulting in a write-down on certain inventories of $2.3 million, which is included in “Cost of sales (excluding depreciation, depletion and amortization) (including related party)” within the Consolidated Statement of Operations for the year ended December 31, 2023. This write-down was largely attributable to elevated carrying costs of the Company’s initial production of separated products given the early stage of ramping the Stage II facilities to normalized production levels.
No write-downs of inventories were recorded for the year ended December 31, 2022.
During the second quarter of 2021, the Company recognized a write-down of a portion of its legacy low-grade stockpile inventory of $1.8 million, after determining that it contained a significant amount of alluvial material that did not meet the Company’s requirement for mill feed and, as a result, was deemed unusable. Since the write-down pertained to a legacy stockpile, it was included in “Other operating costs and expenses” within the Consolidated Statement of Operations for the year ended December 31, 2021, rather than in “Cost of sales (excluding depreciation, depletion and amortization) (including related party).”
v3.24.0.1
PROPERTY, PLANT AND EQUIPMENT
 12 Months Ended
Dec. 31, 2023
Property, Plant and Equipment [Abstract]  
PROPERTY, PLANT AND EQUIPMENT PROPERTY, PLANT AND EQUIPMENT
The Company’s property, plant and equipment consisted of the following:
December 31,
(in thousands)20232022
Land and land improvements$27,091 $16,102 
Buildings and building improvements92,203 15,111 
Machinery and equipment503,145 186,388 
Assets under construction211,848 338,482 
Mineral rights438,395 438,395 
Property, plant and equipment, gross1,272,682 994,478 
Less: Accumulated depreciation and depletion(114,628)(58,735)
Property, plant and equipment, net$1,158,054 $935,743 
Additions to Property, Plant and Equipment: The Company capitalized expenditures related to property, plant and equipment of $280.0 million, $361.2 million and $138.0 million for the years ended December 31, 2023, 2022 and 2021, respectively, including amounts not yet paid (see Note 21, “Supplemental Cash Flow Information”). The capitalized expenditures related primarily to buildings and building improvements, machinery and equipment, and assets under construction to support the Company’s Stage II optimization project, its Fort Worth Facility, its HREE Facility (as defined in Note 16, “Government Grants”), and other assets at Mountain Pass. Additionally, the capitalized expenditures for the year ended December 31, 2022, included the purchase of approximately 18 acres of land in Fort Worth, Texas.
Placement of Assets into Service: During the year ended December 31, 2023, the Company placed assets into service relating to its Stage II optimization project, primarily machinery and equipment, as well as its Stage III initiatives, relating primarily to the land improvements and building of its Fort Worth Facility.
Change in Estimates of Asset Retirement Costs: As a result of decrements to the Company’s ARO during the third quarter of 2022 and fourth quarter of 2021, the carrying amount of the Company’s total property, plant and equipment was reduced by $10.4 million and $8.7 million, respectively, the majority of which pertained to buildings, machinery and equipment, and assets under construction, in the amounts of $0.6 million, $2.7 million and $6.7 million, respectively, and $2.0 million, $2.4 million and $3.2 million, respectively. Additionally, the Company’s depreciation expense for the years ended December 31, 2022 and 2021, was reduced by $2.7 million and $1.1 million, respectively, reflecting the excess of the decrement over the carrying amount of the related property, plant and equipment. See Note 8, “Asset Retirement and Environmental Obligations,” for further information on the decrements.
The Company’s depreciation and depletion expense were as follows:
For the year ended December 31,
(in thousands)202320222021
Depreciation expense$43,998 $5,808 $6,825 
Depletion expense(1)
$11,067 $12,209 $17,200 
(1)At the beginning of the fourth quarter of 2021, as a result of an updated life of mine, the Company revised its estimate of the remaining useful life of the mineral rights to approximately 35 years from approximately 23 years.
The Company recognized $5.5 million of demolition costs for the year ended December 31, 2023, which are included in “Other operating costs and expenses” within the Company’s Consolidated Statements of Operations, incurred in connection with demolishing and removing certain old facilities from the Mountain Pass site that have never been used in the Company’s operations. There were no property, plant and equipment impairments recognized for the years ended December 31, 2023, 2022 and 2021. For information on the Company’s asset-based government grants, which impact the carrying amount of the Company’s property, plant and equipment, see Note 16, “Government Grants.”
v3.24.0.1
EQUITY METHOD INVESTMENT
 12 Months Ended
Dec. 31, 2023
Equity Method Investments and Joint Ventures [Abstract]  
EQUITY METHOD INVESTMENT EQUITY METHOD INVESTMENT
In December 2023, the Company invested $9.7 million of cash in exchange for a 49% equity interest in VREX Holdco Pte. Ltd. (“VREX Holdco”), an entity incorporated in Singapore. Shenghe, a related party to the Company, owns the remaining 51% equity interest in VREX Holdco. VREX Holdco wholly owns Vietnam Rare Earth Company Limited (“VREX”), which owns
and operates a metal processing plant and related facilities in Vietnam. As discussed in Note 20, “Related-Party Transactions,” in October 2023, the Company entered into the Tolling Agreement (as defined in Note 20, “Related-Party Transactions”) with VREX Holdco whereby VREX Holdco causes VREX to process the Company’s NdPr oxide into NdPr metal for delivery to the Company’s customers globally.
The Company determined that VREX Holdco is a variable interest entity, but that the Company is not the primary beneficiary since it does not meet both of the following characteristics: (i) have the power to direct the activities that most significantly impact the economic performance of VREX Holdco and (ii) have the obligation to absorb losses or the right to receive benefits from VREX Holdco that could potentially be significant to VREX Holdco. In the Company’s determination that it is not the primary beneficiary, among other factors, it considered that all major decisions regarding the operations, capital structure and financial condition of VREX Holdco and VREX are subject to approval by VREX Holdco’s board of directors, which is not controlled by the Company. In addition, Shenghe is responsible for the day-to-day project management and operations of VREX Holdco and VREX. Consequently, the Company does not consolidate VREX Holdco, and instead, accounts for its investment in VREX Holdco under the equity method of accounting as it has the ability to exercise significant influence, but not control, over VREX Holdco’s operating and financial policies via its seats on the board of directors and its related party agreements.
As of December 31, 2023, the difference between the carrying amount of the Company’s investment in VREX Holdco, which was $9.7 million, and the amount of underlying equity in the net assets of the investee substantially relates to equity method goodwill, which is not amortized by the Company as a basis difference. The Company records its share of VREX Holdco’s net income or loss on a one-quarter lag due to the timing of when the investee’s financial statements become available. Due to the timing of the investment and the one-quarter lag, the Company did not record any income or loss from this equity method investment during the year ended December 31, 2023. With the exception of the initial investment, there were no contributions to, or distributions received from, VREX Holdco during the year ended December 31, 2023.
The Company capitalizes to inventories the tolling fees paid to VREX Holdco pursuant to the Tolling Agreement. To the extent intra-entity profits or losses remain in the Company’s inventories balance as of each reporting period date, the Company will eliminate its proportional share of such profits or losses until the inventory is sold to an unrelated party. As of December 31, 2023, the tolling fees capitalized to inventories subject to elimination were immaterial. See Note 20, “Related-Party Transactions,” for a discussion on the transactions between the Company and VREX Holdco during the year ended December 31, 2023.
As of December 31, 2023, the Company evaluated its equity method investment for impairment to determine if there were any events or changes in circumstances that would indicate if the carrying amount of its investment had experienced an “other-than-temporary” decline in value. As a result, no impairment charge was recorded during the year ended December 31, 2023.
v3.24.0.1
INTANGIBLE ASSETS
 12 Months Ended
Dec. 31, 2023
Goodwill and Intangible Assets Disclosure [Abstract]  
INTANGIBLE ASSETS INTANGIBLE ASSETS
In August 2023, the Company acquired a license to use patented technology, technical know-how, and other intellectual property pertaining to the development and manufacturing of magnetic products in exchange for 435,729 shares of the Company’s common stock. Pursuant to the terms of the agreement to acquire the license, 152,504 shares were issued immediately and the remaining shares will be issued as follows: 43,573 shares on each of the first, second, and third anniversaries of the acquisition date and an additional 152,506 shares on the fourth anniversary of the acquisition date.
Upon obtaining the license, the Company recorded a definite-lived intangible asset in the amount of $9.0 million, based on the closing price of the Company’s common stock on the acquisition date. The intangible asset will be amortized on a straight-line basis, with no estimated residual value, over the estimated useful life of 7.5 years, which the Company based on the life of the patents associated with the licensed technology.
Contemporaneous with the acquisition of the license, the Company entered into a consulting agreement in support of integrating the licensed technology and know-how into its existing processes aimed at the development of magnetic products. Unless earlier terminated, under the consulting agreement, the Company will pay a total of approximately $15 million over the next four years, of which, the first payment will be in cash on the first anniversary of the consulting agreement and the payments pertaining to the second, third, and fourth anniversaries of the consulting agreement may be settled in cash or shares of the Company’s common stock at the Company’s election. The Company will ratably record an expense over the four years unless the costs qualify for capitalization.
The Company’s intangible assets were as follows:
December 31,
(in thousands)20232022
Intangible assets with indefinite lives:
Emissions allowances$316 $89 
Intangible assets with definite lives:
Patent and intellectual property license8,963 — 
Less: Accumulated amortization (398)— 
Patent and intellectual property license, net8,565 — 
Intangible assets, net
$8,881 $89 
Amortization expense related to amortizing intangible assets was $0.4 million for the year ended December 31, 2023. There was no amortization expense related to amortizing intangible assets recognized for years ended December 31, 2022 and 2021. No impairment charges were recorded during the years ended December 31, 2023, 2022 and 2021.
The following table presents the estimated amortization expense based on amortizing intangible assets as of December 31, 2023:
(in thousands)
Period:
2024$1,195 
20251,195 
20261,195 
20271,195 
20281,195 
Thereafter2,590 
Total$8,565 
v3.24.0.1
ASSET RETIREMENT AND ENVIRONMENTAL OBLIGATIONS
 12 Months Ended
Dec. 31, 2023
Asset Retirement Obligation And Environmental Remediation Obligations [Abstract]  
ASSET RETIREMENT AND ENVIRONMENTAL OBLIGATIONS ASSET RETIREMENT AND ENVIRONMENTAL OBLIGATIONS
Asset Retirement Obligations
The Company estimates ARO based on the requirements to reclaim certain land areas associated with mineral extraction activities and certain related facilities at Mountain Pass. Minor reclamation activities related to discrete portions of the Company’s operations are ongoing. As of December 31, 2023, the Company estimated a significant portion of the cash outflows for major reclamation activities including the retirement of Mountain Pass will be incurred beginning in 2056.
In June 2021, San Bernardino County approved a re-zoning request for certain of the Company’s properties such that certain of the Company’s processing and separations facilities would be zoned for industrial end uses as opposed to the prior “resource conservation” designation. In September 2022, and as a result of the re-zoning of this land, the Company received final approval from San Bernardino County and the Division of Mine Reclamation (California) on a revised reclamation plan. The revision removed from the regulatory oversight under The Surface Mining and Reclamation Act of 1975 the majority of the buildings and equipment used in the processing and separations facilities, including the land underlying such buildings and equipment.
In the third quarter of 2022, as a result of the final approval of the reclamation plan, the Company revised its estimated cash flows pertaining to the settlement of the reclamation and removal activities associated with Mountain Pass, including removing the previous estimates of the cash flows associated with the processing and separations facilities that no longer require reclamation. The changes in estimates resulted in an ARO decrement of $13.1 million, of which $10.4 million reduced the carrying amounts of the associated property, plant and equipment, and $2.7 million, reflecting the excess of the decrement over the carrying amount of the related property, plant and equipment, was recorded as a reduction to depreciation expense for the year ended December 31, 2022.
In the fourth quarter of 2021, the Company revised its estimated timing and cash flows pertaining to the settlement of the reclamation and removal activities associated with Mountain Pass as a result of an updated life of mine where the Company
determined that the estimated commencement of the reclamation and removal activities would then occur in 2056 and 2057 for a significant portion of the assets requiring reclamation at the time. The changes in estimates resulted in an ARO decrement of $9.8 million, of which $8.7 million reduced the carrying amounts of the associated property, plant and equipment, and $1.1 million, reflecting the excess of the decrement over the carrying amount of the related property, plant and equipment, was recorded as a reduction to depreciation expense for the year ended December 31, 2021.
The following is a summary of the Company’s ARO:
December 31,
(in thousands)20232022
Beginning balance$5,475 $17,757 
Obligations settled(180)(144)
Accretion expense407 976 
Revision in estimated cash flows
— (13,114)
Ending balance$5,702 $5,475 
The balance as of both December 31, 2023 and 2022, included current portions of $0.2 million, which are included in “Other current liabilities” within the Company’s Consolidated Balance Sheets. The total estimated future undiscounted cash flows required to satisfy the Company’s ARO as of December 31, 2023 and 2022, were $50.2 million and $50.4 million, respectively. As of December 31, 2023, the credit-adjusted risk-free rate ranged between 6.5% and 12.0% depending on the timing of expected settlement and when the increment was recognized. There were no significant increments or decrements for the year ended December 31, 2023, and there were no significant increments for the years ended December 31, 2022 and 2021.
Environmental Obligations
The Company has certain environmental monitoring and remediation obligations related to the monitoring of groundwater contamination. The Company engaged an environmental consultant to develop a remediation plan and remediation cost projections based upon that plan. Utilizing the consultant’s plan, the Company developed an estimate of future cash payments for the environmental obligations.
As of December 31, 2023, the Company estimated the cash outflows related to these environmental activities will be incurred annually over the next 24 years. The Company’s environmental obligations are measured at the expected value of future cash outflows discounted to their present value using a discount rate of 2.93%. There were no significant changes in the estimated remaining costs for the years ended December 31, 2023, 2022 and 2021.
The total estimated aggregate undiscounted cost of $26.7 million and $27.2 million as of December 31, 2023 and 2022, respectively, principally related to water monitoring activities required by state and local agencies. Based on the Company’s estimate of the cost and timing and the assumption that payments are considered to be fixed and reliably determinable, the Company has discounted the liability. The balance as of both December 31, 2023 and 2022, included current portions of $0.5 million, which are included in “Other current liabilities” within the Company’s Consolidated Balance Sheets.
As of December 31, 2023, the total environmental costs were as follows (in thousands):
Year ending December 31,
2024$536 
2025552 
2026569 
2027587 
2028605 
Thereafter23,806 
Total26,655 
Effect of discounting(9,574)
Total environmental obligations$17,081 
Financial Assurances
The Company is required to provide certain government agencies with financial assurances relating to closure and reclamation obligations. As of December 31, 2023 and 2022, the Company had financial assurance requirements of $45.4 million and $43.5 million, respectively, which were satisfied with surety bonds placed with applicable California state and regional agencies.
v3.24.0.1
ACCRUED EXPENSES
 12 Months Ended
Dec. 31, 2023
Payables and Accruals [Abstract]  
ACCRUED LIABILITIES ACCRUED LIABILITIES
The Company’s accrued liabilities consisted of the following:
December 31,
(in thousands)20232022
Accrued payroll and related
$14,499 $10,909 
Accrued construction costs
46,976 39,226 
Accrued taxes
3,373 281 
Other accrued liabilities
9,091 6,523 
Accrued liabilities
$73,939 $56,939 
v3.24.0.1
DEBT OBLIGATIONS
 12 Months Ended
Dec. 31, 2023
Debt Disclosure [Abstract]  
DEBT OBLIGATIONS DEBT OBLIGATIONS
The Company’s long-term debt was as follows:
December 31,
(in thousands)20232022
Convertible Notes due 2026$690,000 $690,000 
Less: Unamortized debt issuance costs(8,020)(11,556)
Long-term debt, net
$681,980 $678,444 
Convertible Notes
On March 26, 2021, the Company issued $690.0 million aggregate principal amount of 0.25% unsecured green convertible senior notes that mature, unless earlier converted, redeemed or repurchased, on April 1, 2026 (the “Convertible Notes”), at a price of par. Interest on the Convertible Notes is payable on April 1st and October 1st of each year, beginning on October 1, 2021. The Convertible Notes may, at the Company’s election, be settled in cash, shares of common stock of the Company, or a combination thereof. The Company has the option to redeem the Convertible Notes, in whole or in part, beginning on April 5, 2024. The Company received net proceeds of $672.3 million from the issuance of the Convertible Notes.
The Convertible Notes are convertible into shares of the Company’s common stock at an initial conversion price of $44.28 per share, or 22.5861 shares, per $1,000 principal amount of notes, subject to adjustment upon the occurrence of certain corporate events. However, in no event will the conversion price exceed 28.5714 shares of common stock per $1,000 principal amount of the Convertible Notes. As of December 31, 2023, based on the initial conversion price, the maximum number of shares that could be issued to satisfy the conversion feature of the Convertible Notes was 19,714,266. The Convertible Notes’ if-converted value did not exceed its principal amount as of December 31, 2023.
Prior to January 1, 2026, at their election, holders of the Convertible Notes may convert their outstanding notes under the following circumstances: (i) during any calendar quarter commencing with the third quarter of 2021 if the last reported sale price of the Company’s common stock for at least 20 trading days (whether or not consecutive) during the period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price on each applicable trading day; (ii) during the five business day period after any five consecutive trading day period (the “measurement period”) in which the trading price (as defined in the indenture governing the Convertible Notes) per $1,000 principal amount of Convertible Notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of the Company’s common stock and the conversion rate on each such trading day; (iii) if the Company calls any or all of the Convertible Notes for redemption, at any time prior to the close of business on the scheduled trading day immediately preceding the redemption date; or (iv) upon the occurrence of specified corporate events set forth in the indenture governing the Convertible Notes. On or after January 1, 2026, and prior to
the maturity date of the Convertible Notes, holders may convert their outstanding notes at any time, regardless of the foregoing circumstances.
If the Company undergoes a fundamental change (as defined in the indenture governing the Convertible Notes), holders may require it to repurchase for cash all or any portion of their outstanding notes at a price equal to 100% of the principal amount of the notes to be repurchased, plus accrued and unpaid interest to, but excluding, the fundamental change repurchase date. In addition, following certain corporate events that occur prior to the maturity date of the Convertible Notes or if the Company delivers a notice of redemption, it will, in certain circumstances, increase the conversion rate for holders who elect to convert their outstanding notes in connection with such corporate event or notice of redemption, as the case may be.
Interest expense related to the Convertible Notes was as follows:
For the year ended December 31,
(in thousands)202320222021
Coupon interest$1,725 $1,725 $1,318 
Amortization of debt issuance costs3,536 3,517 2,675 
Convertible Notes interest expense$5,261 $5,242 $3,993 
The debt issuance costs are being amortized to interest expense over the term of the Convertible Notes at an effective interest rate of 0.51%. The remaining term of the Convertible Notes was 2.3 years as of December 31, 2023.
Equipment Notes
The Company has financing agreements for the purchase of certain equipment, including trucks, tractors, loaders, graders, and various other machinery. The Company’s equipment notes, which are secured by the purchased equipment, have terms of between 4 to 5 years and interest rates of between 0.0% and 6.5% per annum. See also Note 21, “Supplemental Cash Flow Information.”
The current and non-current portions of the equipment notes, which are included within the Consolidated Balance Sheets in “Other current liabilities” and “Other non-current liabilities,” respectively, were as follows:
December 31,
(in thousands)20232022
Equipment notes
Current$2,106 $2,392 
Non-current2,637 4,743 
$4,743 $7,135 
Paycheck Protection Loan
In April 2020, the Company obtained a loan of $3.4 million pursuant to the Paycheck Protection Program under the CARES Act (the “Paycheck Protection Loan”). In June 2021, the Company received notification from the Small Business Administration that the Paycheck Protection Loan and related accrued interest was forgiven. Consequently, for the year ended December 31, 2021, the Company recorded a gain on forgiveness of the Paycheck Protection Loan in the amount of $3.4 million, which is included in “Other income, net” within the Company’s Consolidated Statements of Operations.
Interest expense, net
Interest expense, net, was as follows:
For the year ended December 31,
(in thousands)202320222021
Interest expense$5,580 $6,146 $9,168 
Interest capitalized to property, plant and equipment, net(326)(360)(264)
Interest expense, net$5,254 $5,786 $8,904 
Debt Maturities
The following is a schedule of debt repayments as of December 31, 2023:
(in thousands)Convertible NotesEquipment Notes
Year ending December 31,
2024$— $2,106 
2025— 2,098 
2026690,000 539 
2027— — 
2028— — 
Thereafter— — 
Total minimum payments$690,000 $4,743 
As of December 31, 2023, none of the agreements governing the Company’s indebtedness contain financial covenants.
v3.24.0.1
LEASES
 12 Months Ended
Dec. 31, 2023
Leases [Abstract]  
LEASES LEASES
The Company has operating and finance leases for certain office space, warehouses, vehicles and equipment used in its operations, with lease terms ranging from one month to nine years. The majority of these leases require monthly lease payments that may be subject to annual increases throughout the lease term. Certain of these leases also include renewal options at the election of the Company to renew or extend the lease for an additional one to five years. The Company’s lease agreements do not contain material residual value guarantees or restrictive covenants. As of December 31, 2023, the Company was not reasonably certain of exercising any material purchase, renewal, or termination options contained within its lease agreements. No ROU asset impairment charges were recorded during the years ended December 31, 2023, 2022 and 2021.
In November 2021, the Company entered into a lease agreement for corporate office space. The lease commenced in the second quarter of 2023, and at lease commencement, the Company recorded an operating lease liability of $7.3 million and an ROU asset of $10.3 million, primarily comprised of the lease liability as well as $2.9 million of payments for lessor-owned tenant improvements. The lease has an initial term of 91 months expiring in October 2030, with an option to renew for one five-year period at the election of the Company. Excluding rent abatement in the first year of the lease, the initial annual base rent payment is $1.2 million, subject to an annual escalator.
Total lease cost included the following components:
Location on Consolidated Statements of OperationsFor the year ended December 31,
(in thousands)202320222021
Operating lease cost
Primarily Selling, general and administrative
$1,328 $424 $780 
Finance lease cost
Amortization of right-of-use assetsDepreciation, depletion and amortization246 339 357 
Interest on lease liabilitiesInterest expense, net32 44 60 
278 383 417 
Short-term lease cost
Primarily Cost of sales (excluding depreciation, depletion and amortization) (including related party)
2,134 1,509 1,163 
$3,740 $2,316 $2,360 
Information related to lease terms and discount rates was as follows:
December 31,
20232022
Weighted-average remaining lease term:
Operating leases6.6 years1.2 years
Finance leases4.4 years1.8 years
Weighted-average discount rate:
Operating leases6.9 %3.1 %
Finance leases6.0 %6.3 %
As of December 31, 2023, the maturities of the Company’s operating and finance lease liabilities were as follows:
(in thousands)Operating LeasesFinance Leases
Period:
2024$1,452 $228 
20251,472 179 
20261,362 59 
20271,370 54 
20281,403 54 
Thereafter2,663 106 
Total lease payments9,722 680 
Less: Imputed interest(1,934)(97)
Total$7,788 $583 
Supplemental disclosure for the Consolidated Balance Sheets related to the Company’s operating and finance leases is as follows:
Location on Consolidated Balance Sheets
December 31,
(in thousands)20232022
Operating leases:
Right-of-use assetsOperating lease right-of-use assets$10,065 $99 
Operating lease liability, currentOther current liabilities$959 $84 
Operating lease liability, non-current
Operating lease liabilities
6,829 15 
Total operating lease liabilities$7,788 $99 
Finance leases:
Right-of-use assetsOther non-current assets$591 $451 
Finance lease liability, currentOther current liabilities$195 $354 
Finance lease liability, non-currentOther non-current liabilities388 242 
Total finance lease liabilities$583 $596 
LEASES LEASES
The Company has operating and finance leases for certain office space, warehouses, vehicles and equipment used in its operations, with lease terms ranging from one month to nine years. The majority of these leases require monthly lease payments that may be subject to annual increases throughout the lease term. Certain of these leases also include renewal options at the election of the Company to renew or extend the lease for an additional one to five years. The Company’s lease agreements do not contain material residual value guarantees or restrictive covenants. As of December 31, 2023, the Company was not reasonably certain of exercising any material purchase, renewal, or termination options contained within its lease agreements. No ROU asset impairment charges were recorded during the years ended December 31, 2023, 2022 and 2021.
In November 2021, the Company entered into a lease agreement for corporate office space. The lease commenced in the second quarter of 2023, and at lease commencement, the Company recorded an operating lease liability of $7.3 million and an ROU asset of $10.3 million, primarily comprised of the lease liability as well as $2.9 million of payments for lessor-owned tenant improvements. The lease has an initial term of 91 months expiring in October 2030, with an option to renew for one five-year period at the election of the Company. Excluding rent abatement in the first year of the lease, the initial annual base rent payment is $1.2 million, subject to an annual escalator.
Total lease cost included the following components:
Location on Consolidated Statements of OperationsFor the year ended December 31,
(in thousands)202320222021
Operating lease cost
Primarily Selling, general and administrative
$1,328 $424 $780 
Finance lease cost
Amortization of right-of-use assetsDepreciation, depletion and amortization246 339 357 
Interest on lease liabilitiesInterest expense, net32 44 60 
278 383 417 
Short-term lease cost
Primarily Cost of sales (excluding depreciation, depletion and amortization) (including related party)
2,134 1,509 1,163 
$3,740 $2,316 $2,360 
Information related to lease terms and discount rates was as follows:
December 31,
20232022
Weighted-average remaining lease term:
Operating leases6.6 years1.2 years
Finance leases4.4 years1.8 years
Weighted-average discount rate:
Operating leases6.9 %3.1 %
Finance leases6.0 %6.3 %
As of December 31, 2023, the maturities of the Company’s operating and finance lease liabilities were as follows:
(in thousands)Operating LeasesFinance Leases
Period:
2024$1,452 $228 
20251,472 179 
20261,362 59 
20271,370 54 
20281,403 54 
Thereafter2,663 106 
Total lease payments9,722 680 
Less: Imputed interest(1,934)(97)
Total$7,788 $583 
Supplemental disclosure for the Consolidated Balance Sheets related to the Company’s operating and finance leases is as follows:
Location on Consolidated Balance Sheets
December 31,
(in thousands)20232022
Operating leases:
Right-of-use assetsOperating lease right-of-use assets$10,065 $99 
Operating lease liability, currentOther current liabilities$959 $84 
Operating lease liability, non-current
Operating lease liabilities
6,829 15 
Total operating lease liabilities$7,788 $99 
Finance leases:
Right-of-use assetsOther non-current assets$591 $451 
Finance lease liability, currentOther current liabilities$195 $354 
Finance lease liability, non-currentOther non-current liabilities388 242 
Total finance lease liabilities$583 $596 
v3.24.0.1
INCOME TAXES
 12 Months Ended
Dec. 31, 2023
Income Tax Disclosure [Abstract]  
INCOME TAXES INCOME TAXES
Income tax expense consisted of the following:
For the year ended December 31,
(in thousands)202320222021
Current:
Federal$(178)$(24,382)$(4,818)
State(135)(9,977)(2,915)
Total current(313)(34,359)(7,733)
Deferred:
Federal(11,334)(19,236)(15,851)
State2,879 1,447 (1,574)
Total deferred(8,455)(17,789)(17,425)
Total tax expense
$(8,768)$(52,148)$(25,158)
Income before income taxes, by tax jurisdiction, was as follows:
For the year ended December 31,
(in thousands)202320222021
United States$33,075 $341,152 $160,195 
Income taxes differed from the amounts computed by applying the U.S. federal income tax rate of 21% to pretax income as a result of the following:
For the year ended December 31,
202320222021
(in thousands, except tax rates)PercentAmountPercentAmountPercentAmount
Computed income tax expense at the statutory rate
21.0 %$(6,946)21.0 %$(71,642)21.0 %$(33,641)
Changes resulting from:
State and local income taxes, net of federal benefits2.6 %(867)3.3 %(11,395)2.7 %(4,288)
Limitation on officer’s compensation11.0 %(3,640)2.3 %(8,067)1.7 %(2,638)
Depletion in excess of basis— %— (4.5)%15,248 (6.1)%9,663 
Paycheck Protection Loan forgiveness— %— — %— (0.5)%714 
Foreign-derived intangible income— %— (4.0)%13,676 (1.8)%2,886 
California Competes Tax Credit, net of federal detriment(11.3)%3,753 (0.9)%3,160 (1.2)%1,975 
Excess tax benefits (expense) on stock-based compensation
0.6 %(190)(1.0)%3,575 (0.6)%974 
Valuation allowance4.1 %(1,360)(0.8)%2,845 0.5 %(821)
Section 45X Advanced Manufacturing Credit
(0.1)%38 — %— — %— 
State rate change and other state adjustments
(1.6)%514 — %— — %— 
Other, net0.2 %(70)(0.1)%452 — %18 
Total effective tax rate and income tax expense
26.5 %$(8,768)15.3 %$(52,148)15.7 %$(25,158)
The tax effects of temporary differences that gave rise to significant portions of the deferred income tax assets and deferred income tax liabilities were as follows:
December 31,
(in thousands)20232022
Deferred tax assets:
Asset retirement and environmental obligations$5,640 $5,643 
Net operating losses25,107 — 
Inventories15,310 12,448 
Research and experimental costs960 691 
Stock-based compensation5,065 3,785 
Organization costs688 776 
Lease liabilities
2,084 173 
Credits3,057 346 
Other439 178 
Gross deferred tax assets58,350 24,040 
Less: Valuation allowance(1,706)(346)
Net deferred tax assets56,644 23,694 
Deferred tax liabilities:
Property, plant and equipment(83,834)(36,481)
Prepaid expenses(520)(1,567)
ROU assets
(2,638)(138)
Deferred revenue(3,270)(6,604)
Mineral rights(97,127)(101,195)
Other(48)(62)
Total deferred tax liabilities(187,437)(146,047)
Non-current deferred tax liabilities, net$(130,793)$(122,353)
As of December 31, 2023 and 2022, the Company had net operating loss carryforwards for federal income tax purposes of $119.6 million and zero, respectively, and did not have any in either period for state income tax purposes. The federal net operating loss may be carried forward indefinitely. As of December 31, 2023, the Company considered the positive and negative evidence to determine the need for a valuation allowance to offset its deferred tax assets and has concluded that it is more likely than not that, with the exception of certain deferred tax assets related to California Alternative Minimum Tax credits, its deferred tax assets will be realized through future taxable temporary differences, principally resulting from the deferred tax liability recorded from the acquisition of Secure Natural Resources LLC (“SNR”) in the 2020 tax year.
During the fourth quarter of 2021, the Company received notice from the State of California that it had been awarded a California Competes Tax Credit (“CCTC”) of $14.8 million that is available to be offset against the Company’s California state income tax liability over the next several years. The credit is allocated in varying amounts over a five-year period based on the Company’s ability to meet certain milestones related to California employees hired, the annual wage of these employees, and the capital investments made by the Company in California. Once the annual milestones are met, a credit amount is awarded. However, a portion of the credit could be “clawed back” if the milestones are not continually met for each of the three following years. For the years ended December 31, 2023, 2022, and 2021, it was determined that the Company had met the relevant annual milestones for the CCTC and as a result, the Company recorded a credit of $4.8 million, $4.0 million, and $2.5 million, respectively, which resulted in an income tax benefit and a reduction to the Company’s California state income tax payable for the 2023, 2022 and 2021 tax years.
In August 2022, the U.S. government enacted the Inflation Reduction Act of 2022, which, among other things, provides several tax incentives to promote clean energy adoption for tax years beginning after December 31, 2022. Specifically, the Section 45X Advanced Manufacturing Production Credit (the “45X Credit”) provides a credit equal to 10% of eligible “production costs incurred” with respect to the production and sale of critical minerals, including NdPr oxide. For more information on the 45X Credit, see Note 16, “Government Grants.”
The Company has evaluated its tax positions for the years ended December 31, 2023, 2022 and 2021, and determined that there were no uncertain tax positions requiring recognition in the Consolidated Financial Statements. The tax years from 2020 onward remain open to examination by the taxing jurisdictions to which the Company is subject.
v3.24.0.1
COMMITMENTS AND CONTINGENCIES
 12 Months Ended
Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]  
COMMITMENTS AND CONTINGENCIES COMMITMENTS AND CONTINGENCIES
Litigation: The Company may become party to lawsuits, administrative proceedings and government investigations, including environmental, regulatory, construction, and other matters, in the ordinary course of business. Large, and sometimes unspecified, damages or penalties may be sought in some matters, and certain matters may require years to resolve. Other than the matter described below, the Company is not aware of any pending or threatened litigation that it believes would have a material adverse effect on its Consolidated Financial Statements.
The Company is currently in dispute with a general contractor for a construction project, which may go to binding arbitration. The Company disputes that it owes any monies in connection with this construction project. The Company is unable to estimate a range of loss, if any, at this time. If an unfavorable outcome were to occur in the case, it is possible that the impact could be material to the Company’s Consolidated Financial Statements in the period in which any such outcome becomes probable and reasonably estimable.
401(k) Plan: The Company maintains a qualified defined contribution retirement plan under the provisions of Section 401(k) of the Internal Revenue Code, which covers all eligible employees (the “MP 401(k) Plan”). Under the MP 401(k) Plan, eligible employees may contribute up to 90% of their pretax salary, subject to the Internal Revenue Service annual contribution limits. The Company makes a discretionary match contribution, where applicable, of 100% of employees’ elective salary deferrals, up to a maximum of 4% of eligible employee compensation. For the years ended December 31, 2023, 2022, and 2021, the Company recognized contribution expense of $2.0 million, $0.9 million, and $0.6 million, respectively.
v3.24.0.1
STOCKHOLDERS’ EQUITY
 12 Months Ended
Dec. 31, 2023
Equity [Abstract]  
STOCKHOLDERS’ EQUITY STOCKHOLDERS’ EQUITY
Common Stock and Preferred Stock
The Company’s certificate of incorporation authorizes it to issue up to 500,000,000 shares, consisting of (i) 450,000,000 shares of common stock and (ii) 50,000,000 shares of preferred stock, each with a par value of $0.0001 per share.
Public Warrants
Warrants to purchase 11,499,968 shares of the Company’s common stock at $11.50 per share (the “Public Warrants”) were issued in connection with the initial public offering of Fortress Value Acquisition Corp., the special purpose acquisition company that acquired MP Mine Operations LLC, a Delaware limited liability company (“MPMO”) and SNR on November 17, 2020 (the “Business Combination”), pursuant to the Warrant Agreement, dated April 29, 2020 (the “Warrant Agreement”), by and between the Company and Continental Stock Transfer & Trust Company (“CST”), as warrant agent. These warrants qualified as equity instruments as they were indexed to the Company’s stock and settlement in shares was within the Company’s control.
On May 4, 2021, at the direction of the Company, CST, in its capacity as warrant agent, delivered a notice of redemption to each of the registered holders of the outstanding Public Warrants for a redemption price of $0.01 per warrant (the “Redemption Price”), that remained outstanding on June 7, 2021 (the “Redemption Date”). In accordance with the Warrant Agreement, the Company’s Board of Directors elected to require that, upon delivery of the notice of redemption, all Public Warrants were to be exercised only on a “cashless basis.” Accordingly, a holder exercising a Public Warrant was deemed to pay the $11.50 per warrant exercise price by the surrender of 0.3808 of a share of common stock that such holder would have been entitled to receive upon a cash exercise, resulting in exercising warrant holders receiving 0.6192 of a share of common stock for each Public Warrant surrendered for exercise. All Public Warrants that remained unexercised on the Redemption Date were delisted, voided and no longer exercisable, and the holders had no rights with respect to those Public Warrants, except to receive the Redemption Price.
During the year ended December 31, 2021, the Company issued 7,080,005 shares of its common stock as a result of the cashless exercise of 11,434,455 Public Warrants. The Company redeemed the remaining 65,513 Public Warrants outstanding at the Redemption Date for a nominal amount.
v3.24.0.1
REVENUE RECOGNITION
 12 Months Ended
Dec. 31, 2023
Revenue from Contract with Customer [Abstract]  
REVENUE RECOGNITION REVENUE RECOGNITION
The following table disaggregates the Company’s revenue from contracts with customers by type of good sold, which are transferred to customers at a point in time:
For the year ended December 31,
(in thousands)
202320222021
Rare earth concentrate
$252,468 $517,267 $328,563 
NdPr oxide and metal695 — — 
Other rare earth products
282 10,243 3,389 
Total revenue$253,445 $527,510 $331,952 
The Company evaluates the recognition of revenue based on the criteria set forth in ASC Topic 606, “Revenue from Contracts with Customers.” Given the nature of the Company’s contracts with customers, contract assets and contract liabilities are not material for any period presented. Furthermore, the amount of revenue recognized in the periods presented from performance obligations that were satisfied (or partially satisfied) in previous periods were not material to any period presented. Refer to Note 2, “Significant Accounting Policies,” for the Company’s revenue recognition policies.
Rare earth concentrate revenue is primarily generated from sales to Shenghe under the amended and restated offtake agreement (“A&R Offtake Agreement”) for sales between January 2022 and February 2022, or the Offtake Agreement (as defined in Note 20, “Related-Party Transactions”) for sales beginning in March 2022. The sales price of rare earth concentrate sold to Shenghe under both agreements is based on an agreed-upon price per MT, with an adjustment for the ultimate market price of the product realized by Shenghe upon sales to their customers, including the impact of changes in the exchange rate between the Chinese Yuan and the U.S. dollar.
NdPr oxide and metal revenue was generated from sales that commenced in the fourth quarter of 2023 under individual sales agreements. Other rare earth product revenue was generated primarily from sales of non-concentrate products, including sales to Shenghe of certain stockpiles of rare earth fluoride for the year ended December 31, 2022.
v3.24.0.1
GOVERNMENT GRANTS
 12 Months Ended
Dec. 31, 2023
Government Assistance [Abstract]  
GOVERNMENT GRANTS GOVERNMENT GRANTS
Asset-Based Grants: In November 2020, the Company was awarded a Defense Production Act Title III technology investment agreement (“TIA”) from the Department of Defense (“DOD”) to establish domestic processing for separated light rare earth elements (this “project”) in the amount of $9.6 million. Pursuant to the terms of the TIA, the Company was required to utilize the funds to acquire property and equipment that contribute to the mission of this project. Furthermore, in exchange for these funds, the Company is required to provide the DOD with periodic reporting specific to this project for up to approximately five years.
During the years ended December 31, 2022 and 2021, pursuant to the TIA, the Company received $5.1 million and $4.4 million, respectively, in reimbursements from the DOD. The funds received reduced the carrying amount of certain fixed assets associated with the Company’s Stage II optimization project, which were included in machinery and equipment as of December 31, 2023 and 2022. As of December 31, 2023, the Company is entitled to receive an additional $0.1 million from the DOD under the TIA.
In February 2022, the Company was awarded a $35.0 million contract by the DOD’s Office of Industrial Base Analysis and Sustainment program to design and build a facility to process heavy rare earth elements (“HREE”) at Mountain Pass (the “HREE Facility”) (the “HREE Production Project Agreement”). The Company must utilize the funds to acquire property and equipment that will contribute to commercial-scale production of separated HREE at Mountain Pass. The Company will be paid fixed amounts upon the completion of certain project milestones. In exchange for these funds, the DOD will have certain rights to technical data following the completion of the project. The funds received pursuant to the HREE Production Project Agreement reduce the carrying amount of the fixed assets associated with the HREE Facility. During the year ended December 31, 2023, the Company had received $2.8 million from the DOD under the HREE Production Project Agreement, which reduced the carrying amount of assets under construction.
Income-Based Grants: As mentioned in Note 12, “Income Taxes,” in August 2022, the U.S. government enacted the Inflation Reduction Act of 2022, which, among other things, promotes clean energy adoption by providing several tax incentives for the domestic production and sale of eligible components for tax years beginning after December 31, 2022. Specifically, the 45X Credit provides a credit equal to 10% of eligible “production costs incurred” with respect to the
production and sale of critical minerals, including NdPr oxide. In December 2023, the Internal Revenue Service released proposed regulations on the 45X Credit which, among other things, clarified that the definition of “production costs incurred” excludes direct and indirect materials costs, including costs related to the extraction or acquisition of raw materials.
For corporate taxpayers, the 45X Credit is eligible for the direct pay election, which allows a refund of the credit in excess of tax liability. The Company intends to make this election on its 2023 tax return, and such election is binding, unless revoked, for five years (i.e., through 2027). Accordingly, the Company determined that the 45X Credit is not within the scope of ASC 740, and instead, should be accounted for as an income-based grant. As such, during the period that the 45X Credit is refundable, the Company will recognize such credit as a reduction to either “Cost of sales (excluding depreciation, depletion and amortization) (including related party)” or “Depreciation, depletion and amortization,” within the Company’s Consolidated Statements of Operations, depending on the location of the corresponding expense, in the period the critical mineral is sold to a customer. Within the Company’s Consolidated Balance Sheets, such 45X Credit is reflected in “Government grant receivable” and, when applicable, “Deferred government grant.”
As of December 31, 2023, the 45X Credit in government grant receivable of $19.3 million as well as the related deferred government grant of $19.1 million, of which $1.7 million is included in “Other current liabilities” within the Company’s Consolidated Balance Sheet, primarily related to the inclusion of tax depreciation on assets that support production of critical minerals, including the Company’s Stage II circuits that were placed into service during 2023 and qualify for bonus tax depreciation treatment. The deferred government grant associated with tax depreciation in 2023 will be recognized as a reduction of depreciation expense on a straight-line basis over the remaining estimated useful life of the underlying long-lived assets, which is approximately 11 years. For the year ended December 31, 2023, the benefits recognized from income-based government grants in the Company’s Consolidated Statements of Operations were not material.
v3.24.0.1
STOCK-BASED COMPENSATION
 12 Months Ended
Dec. 31, 2023
Share-Based Payment Arrangement [Abstract]  
STOCK-BASED COMPENSATION STOCK-BASED COMPENSATION
2020 Incentive Plan: In November 2020, the Company’s stockholders approved the MP Materials Corp. 2020 Stock Incentive Plan (the “2020 Incentive Plan”), which permits the Company to issue stock options (incentive and/or non-qualified); stock appreciation rights (“SARs”); restricted stock, restricted stock units (“RSUs”) and other stock awards (“Stock Awards”); and performance awards. As of December 31, 2023, the Company has not issued any stock options or SARs.
Pursuant to the 2020 Incentive Plan, 9,653,671 shares of common stock were initially available for issuance. The number of shares of common stock available under the 2020 Incentive Plan may be increased annually on the first day of each calendar year, beginning with the year ended December 31, 2021, and continuing until (and including) the year ending December 31, 2030, with such annual increase equal to the lesser of (i) 2% of the number of shares of stock issued and outstanding on December 31st of the immediately preceding fiscal year and (ii) an amount determined by the Board of Directors. The number of shares of common stock that remain available for future grants under the 2020 Incentive Plan shall be reduced by the sum of the aggregate number of shares of common stock that become subject to outstanding options, outstanding free-standing SARs, outstanding Stock Awards, and outstanding performance awards denominated in shares of common stock, other than substitute awards. As of December 31, 2023, there were 5,928,540 shares available for future grants under the 2020 Incentive Plan.
Market-Based PSUs: In February 2023, pursuant to the 2020 Incentive Plan, the Compensation Committee of the Company’s Board of Directors adopted a performance share plan (the “2023 Performance Share Plan”). Pursuant to the 2023 Performance Share Plan, for the year ended December 31, 2023, the Company granted 62,709 of market-based performance stock units (“PSUs”) at target, all of which cliff vest after a requisite performance and service period of three years. The PSUs have the potential to be earned at between 0% and 200% of the number of awards granted depending on the level of growth of the Company’s total shareholder return (“TSR”) as compared to the TSR of the S&P 400 Index and the S&P 400 Materials Group over the performance period. The fair value of the market-based PSUs was determined using a Monte Carlo simulation technique.
The following table contains information on the Company’s performance awards:
Number of SharesWeighted-Average Grant Date Fair Value
Nonvested as of January 1, 2023— $— 
Granted62,709 $50.40 
Vested— $— 
Forfeited— $— 
Nonvested as of December 31, 202362,709 $50.40 
As of December 31, 2023, the unamortized compensation cost not yet recognized related to performance awards totaled $2.1 million and the weighted-average period over which the costs are expected to be recognized was 2.0 years.
Stock Awards: Pursuant to the terms and conditions of certain executive employment agreements, in connection with the consummation of the Business Combination, 2,013,006 shares of restricted stock were issued in November 2020, of which 200,000 shares immediately vested and the remainder of shares were to vest ratably pursuant the respective employment agreements over the requisite service period of four years.
The Company granted 805,322, 382,742 and 1,026,387 RSUs to employees during the years ended December 31, 2023, 2022, and 2021, respectively, which, with the exception of 67,700, 36,461 and 80,350 RSUs granted during the years ended December 31, 2023, 2022 and 2021, respectively, that vested immediately, vest ratably in equal installments over the requisite service period of four years.
Additionally, the Company granted 48,177, 23,975 and 18,394 RSUs to non-employee directors during the years ended December 31, 2023, 2022, and 2021, respectively, of which, 10,691, 6,881 and 5,810 vested immediately into tax-deferred stock units (“DSUs”) during the years ended December 31, 2023, 2022 and 2021, respectively. The remaining RSUs granted vest into DSUs upon the earlier of one year after the grant date and the next annual stockholder meeting. The DSUs are settled as shares of common stock of the Company upon the earlier of (i) June 15th of the fifth year after grant, (ii) a change in control of the Company, or (iii) the director’s separation from the Board, unless the director elects to defer settlement until retirement.
The grant date fair value of the Company’s Stock Awards is based on the closing stock price of the Company’s shares of common stock on the date of grant. The weighted-average grant date fair value of Stock Awards granted during the years ended December 31, 2023, 2022, and 2021 was $24.13, $38.52 and $41.24, respectively.
The following table contains information on the Company’s Stock Awards:
Number of SharesWeighted-Average Grant Date Fair Value
Nonvested as of January 1, 20232,208,163 $26.76 
Granted853,499 $24.13 
Vested(841,466)$25.80 
Forfeited(44,475)$28.34 
Nonvested as of December 31, 20232,175,721 $26.06 
As of December 31, 2023, the unamortized compensation cost not yet recognized related to Stock Awards totaled $23.2 million and the weighted-average period over which the costs are expected to be recognized was 1.8 years. The total fair value of Stock Awards that vested during the years ended December 31, 2023, 2022 and 2021, was $20.7 million, $40.0 million and $10.9 million, respectively.
Stock-Based Compensation: The Company’s stock-based compensation and related income tax benefit were recorded as follows:
For the year ended December 31,
(in thousands)202320222021
Cost of sales (excluding depreciation, depletion and amortization) (including related party)
$3,932 $2,853 $4,294 
Selling, general and administrative20,508 28,554 18,246 
Start-up costs
723 119 — 
Advanced projects and development73 254 391 
Total stock-based compensation expense$25,236 $31,780 $22,931 
Stock-based compensation capitalized to property, plant and equipment, net$1,868 $1,286 $— 
Income tax benefit for stock-based compensation arrangements
$— $4,256 $3,185 
v3.24.0.1
FAIR VALUE MEASUREMENTS
 12 Months Ended
Dec. 31, 2023
Fair Value Disclosures [Abstract]  
FAIR VALUE MEASUREMENTS FAIR VALUE MEASUREMENTS
ASC Topic 820, “Fair Value Measurement,” establishes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value. The hierarchy gives the highest priority to unadjusted quoted prices in active markets for identical assets or liabilities (Level 1 measurements) and the lowest priority to unobservable inputs (Level 3 measurements). The three levels of the fair value hierarchy are described below:
Level 1Unadjusted quoted prices in active markets that are accessible at the measurement date for identical, unrestricted assets or liabilities;
Level 2Quoted prices in markets that are not active, quoted prices for similar assets or liabilities in active markets, quoted prices or inputs that are observable, either directly or indirectly, for substantially the full term of the asset or liability and model-based valuation techniques (e.g. the Black-Scholes model) for which all significant inputs are observable in active markets.
Level 3Prices or valuation techniques that require inputs that are both significant to the fair value measurement and unobservable (supported by little or no market activity).
The Company’s assessment of the significance of a particular input to the fair value measurement requires judgment and may affect the valuation of assets and liabilities and their placement within the fair value hierarchy. The following methods and assumptions are used to estimate the fair value of each class of financial instruments for which it is practicable to estimate. The fair value of the Company’s accounts receivable, accounts payable, and accrued liabilities approximates the carrying amounts because of the immediate or short-term maturity of these financial instruments.
Cash, Cash Equivalents and Restricted Cash
The Company’s cash, cash equivalents and restricted cash are classified within Level 1 of the fair value hierarchy. The carrying amounts reported in the Consolidated Balance Sheets approximate the fair value of cash, cash equivalents and restricted cash due to the short-term nature of these assets.
Short-term Investments
The fair value of the Company’s short-term investments, which are classified as available-for-sale securities, is estimated based on quoted prices in active markets and is classified as a Level 1 measurement.
Convertible Notes
The fair value of the Company’s Convertible Notes is estimated based on quoted prices in active markets and is classified as a Level 1 measurement.
Equipment Notes
The Company’s equipment notes are classified within Level 2 of the fair value hierarchy because there are inputs that are directly observable for substantially the full term of the liability. Model-based valuation techniques for which all significant
inputs are observable in active markets were used to calculate the fair values of liabilities classified within Level 2 of the fair value hierarchy.
Assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The carrying amounts and estimated fair values by input level of the Company’s financial instruments were as follows:
December 31, 2023
(in thousands)
Carrying
Amount
Fair ValueLevel 1Level 2Level 3
Financial assets:
Cash and cash equivalents$263,351 $263,351 $263,351 $— $— 
Short-term investments$734,493 $734,493 $734,493 $— $— 
Restricted cash$1,637 $1,637 $1,637 $— $— 
Financial liabilities:
Convertible Notes$681,980 $619,496 $619,496 $— $— 
Equipment notes$4,743 $4,628 $— $4,628 $— 
December 31, 2022
(in thousands)
Carrying
Amount
Fair Value
Level 1Level 2Level 3
Financial assets:
Cash and cash equivalents$136,627 $136,627 $136,627 $— $— 
Short-term investments$1,045,718 $1,045,718 $1,045,718 $— $— 
Restricted cash$6,882 $6,882 $6,882 $— $— 
Financial liabilities:
Convertible Notes$678,444 $610,650 $610,650 $— $— 
Equipment notes$7,135 $6,807 $— $6,807 $— 
v3.24.0.1
EARNINGS PER SHARE
 12 Months Ended
Dec. 31, 2023
Earnings Per Share [Abstract]  
EARNINGS PER SHARE EARNINGS PER SHARE
Basic EPS is computed by dividing net income by the weighted-average number of common shares outstanding during the period. Diluted EPS is computed by dividing net income by the weighted-average number of common shares outstanding plus the effect of dilutive potential common shares outstanding during the period using the treasury stock method or the if-converted method, as applicable.
The following table reconciles the weighted-average common shares outstanding used in the calculation of basic EPS to the weighted-average common shares outstanding used in the calculation of diluted EPS:
For the year ended December 31,
202320222021
Weighted-average shares outstanding, basic177,181,661 176,519,203 173,469,546 
Assumed conversion of Public Warrants— — 2,840,624 
Assumed conversion of Convertible Notes— 15,584,409 11,997,860 
Assumed conversion of restricted stock609,326 921,772 1,257,360 
Assumed conversion of RSUs361,225 427,703 278,638 
Weighted-average shares outstanding, diluted178,152,212 193,453,087 189,844,028 
The following table presents potentially dilutive shares that were not included in the computation of diluted EPS because to do so would have been antidilutive:
For the year ended December 31,
202320222021
Convertible Notes
15,584,409 — — 
RSUs3,184 24,442 18,322 
Total15,587,593 24,442 18,322 
The following table presents the calculation of basic and diluted EPS for the Company’s common stock:
For the year ended December 31,
(in thousands, except share and per share data)202320222021
Calculation of basic EPS:
Net income
$24,307 $289,004 $135,037 
Weighted-average shares outstanding, basic177,181,661 176,519,203 173,469,546 
Basic EPS$0.14 $1.64 $0.78 
Calculation of diluted EPS:
Net income
$24,307 $289,004 $135,037 
Interest expense, net of tax(1):
Convertible Notes(2)
— 4,441 3,366 
Diluted income
$24,307 $293,445 $138,403 
Weighted-average shares outstanding, diluted178,152,212 193,453,087 189,844,028 
Diluted EPS$0.14 $1.52 $0.73 
(1)The years ended December 31, 2022, and 2021, were tax-effected at a rate of 15.3% and 15.7%, respectively.
(2)The Convertible Notes were antidilutive for the year ended December 31, 2023. Convertible debt becomes antidilutive whenever its interest expense (net of tax) per common share obtainable upon conversion exceeds basic EPS.
v3.24.0.1
RELATED PARTY TRANSACTIONS
 12 Months Ended
Dec. 31, 2023
Related Party Transactions [Abstract]  
RELATED PARTY TRANSACTIONS RELATED-PARTY TRANSACTIONS
Offtake Agreement: In March 2022, the Company entered into an offtake agreement (the “Offtake Agreement”) with Shenghe Resources (Singapore) International Trading Pte. Ltd. (“Shenghe”), a majority-owned subsidiary of Leshan Shenghe Rare Earth Co., Ltd. whose ultimate parent is Shenghe Resources Holding Co., Ltd., a leading global rare earth company listed on the Shanghai Stock Exchange. The Offtake Agreement became effective upon the termination of the amended and restated offtake agreement with Shenghe. The initial term of the Offtake Agreement is two years, with the option to extend the term at the Company’s discretion for an additional one-year period.
Pursuant to the Offtake Agreement, and subject to certain exclusions, Shenghe is obligated to purchase on a “take or pay” basis the rare earth concentrate produced by the Company as the exclusive distributor in China, with certain exceptions for the Company’s direct sales globally. In addition, at the discretion of the Company, Shenghe may be required to purchase on a “take or pay” basis certain non-concentrate rare earth products, although the Company may sell all non-concentrate rare earth products in its sole discretion to customers or end users in any jurisdiction.
The sales price of rare earth concentrate sold to Shenghe is based on an agreed-upon price per metric ton, with an adjustment for the ultimate market price of the product realized by Shenghe upon sales to their customers. The sales price and other terms applicable to a quantity of offtake products are set forth in monthly purchase agreements between the Company and Shenghe. Under the Offtake Agreement, Shenghe is paid a variable commission on net proceeds to the Company.
In January 2024, the Company entered into a new offtake agreement with Shenghe (the “New Offtake Agreement”) that replaced and extended the Offtake Agreement. The initial term of the New Offtake Agreement is two years, with the option for the Company to extend the term for an additional one-year period. The terms of the New Offtake Agreement are substantially the same as those of the Offtake Agreement with the exception of the addition of NdPr metal into the definition of non-concentrate rare earth products.
Tolling Agreement with VREX Holdco: In October 2023, prior to the Company’s investment in VREX Holdco, the Company entered into a tolling agreement with VREX Holdco (the “Tolling Agreement”). Pursuant to the Tolling Agreement, the Company delivers NdPr oxide to VREX Holdco, which VREX Holdco then causes VREX to process into NdPr metal for delivery to the Company’s customers globally. As several of the Company’s potential customers that manufacture magnets outside of China prefer to purchase NdPr metal in addition to NdPr oxide, this Tolling Agreement enables the Company to distribute NdPr products more widely to customers in Japan and other global markets. During the term of the Tolling Agreement, the Company will pay VREX Holdco a processing fee per unit of rare earth metal produced. The Company maintains title to the products and directly enters into sales agreements for the produced NdPr metal. The initial term of the Tolling Agreement is three years and may be renewed for additional three-year terms.
During the year ended December 31, 2023, prior to the Company’s investment in VREX Holdco, the Company made a payment of $1.2 million to VREX Holdco for tolling services, of which, the majority was for services yet to be performed by VREX. Refer to Note 6, “Equity Method Investment,” for additional information on the investment in VREX Holdco.
Revenue and Cost of Sales: The Company’s related-party revenue and cost of sales were as follows:
For the year ended December 31,
(in thousands)202320222021
Revenue:
Rare earth concentrate$242,516 $487,006 $326,599 
Other rare earth products(1)
$— $9,740 $— 
Cost of sales (excluding depreciation, depletion and amortization)
$89,260 $88,681 $75,930 
(1)Represents sales agreements with Shenghe for non-concentrate products, including certain stockpiles of rare earth fluoride.
Purchases of Materials and Supplies: The Company purchases certain reagent products (generally produced by an unrelated third party manufacturer) used in the flotation process as well as other materials from Shenghe in the ordinary course of business. Total purchases for the years ended December 31, 2023, 2022 and 2021, totaled $8.3 million, $18.5 million and $4.8 million, respectively.
Accounts Receivable: As of December 31, 2023 and 2022, $9.2 million and $29.8 million, respectively, of the accounts receivable as stated on the Consolidated Balance Sheets, were receivable from and pertained to sales made to Shenghe in the ordinary course of business.
v3.24.0.1
SUPPLEMENTAL CASH FLOW INFORMATION
 12 Months Ended
Dec. 31, 2023
Additional Cash Flow Elements and Supplemental Cash Flow Information [Abstract]  
SUPPLEMENTAL CASH FLOW INFORMATION SUPPLEMENTAL CASH FLOW INFORMATION
Supplemental cash flow information and non-cash investing and financing activities were as follows:
For the year ended December 31,
(in thousands)202320222021
Supplemental cash flow information:
Cash paid for interest$2,059 $2,096 $1,204 
Cash payments related to income taxes, net$20,105 $18,860 $4,172 
Change in construction payables and accrued construction costs
$18,086 $34,569 $14,082 
Supplemental non-cash investing and financing activities:
Common stock issued to acquire intangible asset
$8,963 $— $— 
Operating ROU assets obtained in exchange for lease liabilities
$7,690 $168 $— 
Finance ROU assets obtained in exchange for lease liabilities
$371 $42 $88 
Property, plant and equipment acquired with equipment notes$— $— $9,407 
Revenue recognized in exchange for debt principal reduction$— $13,566 $54,802 
Paycheck Protection Loan forgiveness$— $— $3,401 
Decrease in estimates of asset retirement costs$— $10,395 $8,713 
v3.24.0.1
Pay vs Performance Disclosure - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Pay vs Performance Disclosure      
Net income $ 24,307 $ 289,004 $ 135,037
v3.24.0.1
Insider Trading Arrangements
 3 Months Ended
Dec. 31, 2023
Trading Arrangements, by Individual  
Rule 10b5-1 Arrangement Adopted false
Non-Rule 10b5-1 Arrangement Adopted false
Rule 10b5-1 Arrangement Terminated false
Non-Rule 10b5-1 Arrangement Terminated false
v3.24.0.1
DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION (Policies)
 12 Months Ended
Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]  
Basis of Presentation The Consolidated Financial Statements of the Company have been prepared in accordance with generally accepted accounting principles in the U.S. (“GAAP”) and with the rules and regulations of the U.S. Securities and Exchange Commission (the “SEC”).
v3.24.0.1
SIGNIFICANT ACCOUNTING POLICIES (Policies)
 12 Months Ended
Dec. 31, 2023
Accounting Policies [Abstract]  
Principles of Consolidation The Consolidated Financial Statements include the accounts of MP Materials Corp. and its subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation.
Concentration of Risk Financial instruments that potentially subject the Company to credit risk consist principally of cash, cash equivalents and short-term investments, and receivables from customers. The Company believes that its credit risk is limited because the Company’s current contracts are with companies that have a reliable payment history. The Company does not believe that it is exposed to any significant risks related to its cash accounts, money market funds, or short-term investments.
As of December 31, 2023, Shenghe was the Company’s principal customer and accounted for more than 90% of revenue. Rare earth concentrate is not quoted on any major commodities market or exchange and demand for rare earth concentrate is currently constrained to a relatively limited number of refiners, a significant majority of which are based in China. Uncertainty exists as to the market price of rare earth oxide (“REO”), as evidenced by the volatility experienced in 2022 and 2023 primarily due to concerns over the global economic conditions and actual or perceived concerns over increases in the supply of or slower growth in the demand for rare earth products. Furthermore, while revenue is generated in the U.S., Shenghe conducts its primary operations in China and may transport and sell products in the Chinese market. Therefore, the Company’s revenue is affected by Shenghe’s ultimate realized prices in China, including the impact of changes in the exchange rate between the Chinese Yuan and the U.S. dollar. In addition, the ongoing economic conflict between China and the U.S., which has previously resulted in tariffs and trade barriers, may negatively affect the Company’s business and results of operations. See Note 20, “Related-Party Transactions,” for additional information.
Use of Estimates The preparation of the Consolidated Financial Statements in conformity with GAAP requires management to make estimates and assumptions that affect (i) the reported amounts of assets and liabilities, (ii) the disclosure of contingent assets and liabilities at the date of the Consolidated Financial Statements, and (iii) the reported amounts of revenues and expenses during the reporting period. The more significant areas requiring the use of management estimates and assumptions relate to the useful lives and recoverability of long-lived assets (such as the effects of mineral reserves and cash flows from operating the mine in determining the life of the mine); the valuation allowance of deferred tax assets; asset retirement and environmental obligations; and determining the net realizable value of inventories. Management bases its estimates on historical experience and on various other assumptions that are believed to be reasonable under the circumstances. Accordingly, actual results may differ from those estimates.
Cash and Cash Equivalents Cash and cash equivalents consist of all cash balances and highly liquid investments, including commercial paper, certificates of deposit, and U.S. treasury and agency securities, with a maturity of three months or less at the time of purchase.
Marketable Securities
The Company’s investments in U.S. treasury and agency securities, commercial paper, and certificates of deposit have been classified and accounted for as available-for-sale securities and the Company reevaluates the classification each reporting period. The Company classifies its available-for-sale securities that do not otherwise meet the requirements to be accounted for as cash equivalents as either current or non-current based on each instrument’s underlying contractual maturity date as well as the Company’s expectations of sales and redemptions within the next twelve months. See Note 3, “Cash, Cash Equivalents and Investments,” for additional information.
Available-for-sale securities are recorded at fair value each reporting period. For unrealized losses in securities that the Company intends to hold and will not more likely than not be required to sell before recovery, the Company further evaluates whether declines in fair value below amortized cost are due to credit or non-credit related factors. The Company considers credit related impairments to be changes in value that are driven by a change in the creditor’s ability to meet its payment obligations and records an allowance and recognizes a corresponding loss when the impairment is incurred.
Unrealized non-credit related losses and unrealized gains are reported, net of income taxes, in “Accumulated other comprehensive income” within the Company’s Consolidated Balance Sheets, until realized. Realized gains and losses are determined based on the specific identification method and are reported in “Other income, net” within the Company’s Consolidated Statements of Operations upon realization. Premiums and discounts are amortized or accreted over the life of the related available-for-sale security as an adjustment to yield using the straight-line method. Interest income is recognized when earned. These amounts are reported in “Other income, net” within the Company’s Consolidated Statements of Operations.
Restricted Cash Restricted cash consists of funds that are contractually restricted as to usage or withdrawal due to legal agreement. The Company determines current or non-current classification based on the expected duration of the restriction. Current and non-current restricted cash is included in “Prepaid expenses and other current assets” and “Other non-current assets,” respectively, within the Consolidated Balance Sheets.
Trade Accounts Receivable Accounts receivable pertain to receivables arising from contracts with customers and are recorded at the invoiced amount and do not bear interest. The Company evaluates its estimate of expected credit losses based on historical experience and current economic conditions for each portfolio of customers, though at present, the amounts are typically concentrated in a single customer.
Inventories Inventories consist of raw materials, supplies, mined ore stockpiles, work in process, and finished goods. Raw materials and supplies consist of spare parts, reagent chemicals, maintenance supplies, and packaging materials used in the production of rare earth products. Mined ore stockpiles represent bastnaesite ore that has been mined and stockpiled for future processing. Work in process consists of bastnaesite ore and separated rare earth products in various stages of the production process, as well as finished and packaged NdPr oxide shipped to tollers for processing into NdPr metal. Finished goods primarily consists of packaged traditional or roasted bastnaesite concentrate as well as finished and packaged NdPr oxide and NdPr metal (including quantities tolled) that is ready for sale.
Raw materials, mined ore stockpiles, work in process, and finished goods are carried at average cost. Supplies are carried at moving average cost. All inventories are carried at the lower of cost or net realizable value, which represents the estimated selling price of the product during the ordinary course of business based on current market conditions less reasonably predictable costs of completion, disposal, and transportation. Inventory cost includes all costs directly attributable to the
manufacturing process, including labor and stripping costs, and an appropriate portion of production overhead costs, including depreciation, based on normal capacity of the production facilities.
Stockpiled ore tonnages are verified by periodic surveys. The Company evaluates the carrying amount of inventory each reporting period, considering recent market prices, slow-moving items, obsolescence, excess inventory levels, and other factors and recognizes related write-downs if it is determined that the inventory is impaired. Mined ore stockpiles that are not expected to be processed within the next twelve months and raw materials and spare parts that are not expected to be consumed within the next twelve months are classified as non-current.
Property, Plant and Equipment Property, plant and equipment are recorded at cost and depreciated over their useful lives. Expenditures for new property, plant and equipment and improvements that extend the useful life or functionality of the assets are recorded at their cost of acquisition or construction. Depreciation on property, plant and equipment is recognized on a straight-line basis over their estimated useful lives, as follows:
Years
Land improvements
10-25
Buildings and building improvements
10-40
Machinery and equipment
3-20
Assets under construction include costs directly attributable to the construction or development of long-lived assets. These costs may include labor and employee benefits associated with the construction of the asset, site preparation, permitting, engineering and design, installation and assembly, procurement, insurance, legal, initial commissioning, and interest on borrowings to finance the construction of the assets. Depreciation is not recorded on the related assets until they are ready for their intended use. Repair and maintenance costs that do not extend the useful life of an asset are expensed as incurred. Gains and losses arising from the sale or disposal of property, plant and equipment are determined as the difference between the proceeds from sale or disposal and the carrying amount of the asset, and are included, along with demolition costs, in “Other operating costs and expenses” within the Company’s Consolidated Statements of Operations.
Property, plant and equipment primarily relate to the Company’s open-pit mine and processing and separations facility at Mountain Pass as well as the building associated with the Company’s Fort Worth Facility. In addition to the mine pit, Mountain Pass includes a crusher and mill/flotation plant, mineral recovery and separation plants, tailings processing and storage facilities, product finishing facilities, on-site evaporation ponds, a combined heat and power plant, water treatment plant, a chlor-alkali plant, as well as laboratory facilities to support research and development activities, offices, warehouses and support infrastructure.
Mineral Rights The Company capitalizes costs for acquiring and leasing mining properties and expenses costs to maintain mineral rights as incurred. Depletion on mineral rights is recognized on a straight-line basis over the estimated remaining useful life of the mine, which was approximately 33 years as of December 31, 2023. The Company determined that the straight-line method of depletion appropriately captures the estimated economic costs of extracting the minerals of the mine across its estimated useful life, and aligns with the benefit obtained from the depletion of the asset consistent with the current mine plan. Mineral rights are classified as a component of “Property, plant and equipment” within the Company’s Consolidated Balance Sheets.
Leases The Company determines if an arrangement is, or contains, a lease at contract inception. In some cases, the Company has determined that its lease arrangements include both lease and non-lease components. The Company has elected to use a practical expedient to account for each separate lease component and its associated non-lease components as a single lease component for the majority of its asset classes. The Company recognizes right-of-use (“ROU”) assets and lease liabilities upon commencement for all leases with a lease term greater than 12 months. The Company has elected to use a practical expedient to not recognize leases with a lease term of 12 months or less in the Consolidated Balance Sheets for the majority of its asset classes. These short-term leases are expensed on a straight-line basis over the lease term.
ROU assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent the Company’s obligation to make lease payments arising from the lease. ROU assets and lease liabilities are recognized at commencement date of the lease based on the present value of lease payments over the lease term. When the rate implicit in the lease cannot be readily determined, the Company utilizes its incremental borrowing rate in determining the present value of the future lease payments. Lease liabilities are accreted each period and reduced for payments. The ROU asset also includes other adjustments, such as for the effects of lease prepayments, initial lease costs, or lease incentives received. The lease term may include periods covered by options to extend or terminate the lease when it is either reasonably certain that the Company will
exercise a renewal option, or reasonably certain it will not exercise an early termination option. For operating leases, lease expense is recognized on a straight-line basis over the lease term. For finance leases, the ROU asset amortizes on a straight-line basis over the shorter of the lease term or the useful life of the underlying asset (or the useful life of the underlying asset if title transfers at the end of the lease term or there is a purchase option the Company is reasonably certain to exercise) and the lease liability accretes interest based on the interest method using the discount rate determined at lease commencement. For operating and finance leases, variable lease payments not included in the lease liability are expensed as incurred unless such costs are capitalized as part of another asset (e.g., inventory). Additionally, ROU assets are subject to impairment testing whenever events or changes in circumstances indicate that their carrying amount may not be recoverable. If the carrying amounts of ROU assets exceed their fair value, the excess amount is recognized as an impairment.
Impairment of Long-Lived Assets Long-lived assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset or asset group may not be recoverable. In estimating undiscounted cash flows, assets are grouped at the lowest level for which there are identifiable cash flows that are largely independent of undiscounted cash flows from other asset groups. The Company’s estimates of undiscounted cash flows are based on numerous assumptions, and it is possible that actual cash flows may differ significantly from estimates, as actual produced reserves, prices, commodity-based and other costs, and closure costs are each subject to significant risks and uncertainties. The estimated undiscounted cash flows used to assess recoverability of long-lived assets and to measure the fair value of the Company’s mining operations are derived from current business plans, which are developed using short-term price forecasts reflective of the current price environment and the Company’s projections for long-term average prices. In addition to short- and long-term price assumptions, other assumptions include estimates of production costs; proven and probable mineral reserve estimates, including the timing and cost to develop and produce the reserves; value beyond proven and probable estimates; and estimated future closure costs.
If the carrying amount of the long-lived asset or asset groups is not recoverable on an undiscounted cash flows basis, an impairment is recognized to the extent that the carrying amount exceeds its fair value. Fair value is determined through various valuation techniques, including discounted cash flow models, quoted market values, and third-party independent appraisals, based on the approach the Company believes a market participant would use.
Equity Method Investments Investments in equity securities are accounted for under the equity method if the Company has the ability to exercise significant influence, but not control, over an investee’s operating and financial policies. Judgment regarding the level of influence includes considering key factors such as the Company’s ownership interest, representation on the board of directors, participation in policy-making decisions and material intra-entity transactions. Under the equity method, an investment’s carrying amount is adjusted for the Company’s share of the investee’s net income or loss (including other comprehensive income or loss), amortization/accretion of certain basis differences (if any), capital contributions to and distributions from an investee, as well as any other-than-temporary impairments.
The Company records its share of an equity method investment’s net income or loss on a one-quarter lag due to the timing of when an investee’s financial statements become available. The Company evaluates material events occurring during the one-quarter lag to determine whether the effects of such events should be reflected or disclosed within the Company’s Consolidated Financial Statements. For intra-entity transactions between the Company and its equity method investee, the Company eliminates its share of profits and losses until realized by the Company or investee. Such elimination is recorded as an adjustment of the carrying amount of the equity method investment.
The Company evaluates its equity method investment for impairment whenever events or changes in circumstances indicate that the carrying amount of its investment may not be recoverable. If such conditions exist, the Company compares the estimated fair value of the investment to its carrying amount to determine if an impairment is indicated, and if so, determines whether the impairment is “other-than-temporary” based on its assessment of all relevant factors, including consideration of the Company’s intent and ability to retain its investment. If the Company determines the decline is other-than-temporary, an impairment is recognized for the excess amount by which the investment’s carrying amount exceeds its fair value.
Intangible Assets Indefinite-lived intangible assets are tested annually for impairment, or more frequently if events or changes in circumstances indicate that it is more likely than not that the assets are impaired. If the carrying amounts of the indefinite-lived intangible assets exceed their fair value, the excess amount is recognized as an impairment. Intangible assets that have a definite life are amortized on a straight-line basis over their estimated useful lives to reflect the expected pattern of economic benefits consumed. The Company reviews the carrying amount of its amortizing intangible assets for possible impairment whenever events or changes in circumstances indicate that their carrying amount may not be recoverable. If the carrying amounts of the amortizing intangible assets exceed their fair value, the excess amount is recognized as an impairment. Once an impairment of an intangible asset has been recorded, it cannot be reversed.
Asset Retirement Obligations The Company recognizes asset retirement obligations (“ARO”) for estimated costs of legally and contractually required closure, dismantlement, and reclamation activities associated with Mountain Pass. ARO are initially recognized at their estimated fair value in the period in which the obligation originates. Fair value is based on the expected timing of reclamation activities, cash flows to perform activities, amount and uncertainty associated with the cash flows, including adjustments for a market risk premium, and discounted using a credit-adjusted risk-free rate. The liability is accreted over time through periodic charges to earnings and reduced as reclamation activities occur with differences between estimated and actual amounts recognized as an adjustment to operating expenses. Accretion of asset retirement obligations is included in “Other operating costs and expenses” within the Company’s Consolidated Statements of Operations.Subsequent increments in expected undiscounted cash flows are measured at their discounted values using updated estimates of the Company’s credit-adjusted risk-free rate applied to the increment only. Subsequent decrements in expected undiscounted cash flows are reduced based on the weighted-average credit-adjusted risk-free rate associated with the obligation. When increments and decrements are caused by a change in the estimated timing of settlement, the Company treats the increase in cash flows in the year of the updated estimate as an increment and the increase in cash flows in the original year as a decrement. Associated asset retirement costs, including the effect of increments and decrements, are recognized as adjustments to the related asset’s carrying amount and depreciated over the related asset’s remaining useful life. If a decrement is greater than the carrying amount of the related asset, the difference is recognized as a reduction to depreciation expense.
Environmental Obligations The Company has certain environmental remediation obligations that primarily relate to groundwater monitoring activities. Estimated remediation costs are accrued based on management’s best estimate at the end of each reporting period of the costs expected to be incurred to settle the obligation when those amounts are probable and estimable. Such cost estimates may include ongoing care, maintenance and monitoring costs associated with remediation activities. Changes in remediation estimates are reflected in earnings in the period the estimate is revised. Remediation costs included in environmental obligations are discounted to their present value when payments are readily estimable, and are discounted using a risk-free rate, which the Company derives from U.S. Treasury yields. Accretion of environmental obligations is included in “Other operating costs and expenses” within the Company’s Consolidated Statements of Operations.
Debt Issuance Costs Costs that are incurred by the Company in connection with the issuance of debt are deferred and amortized to interest expense using the effective interest method over the contractual term of the underlying indebtedness. Debt issuance costs reduce the carrying amount of the associated debt.
Commitments and Contingencies Liabilities for loss contingencies arising from claims, assessments, litigation, fines and penalties, and other sources are recorded when it is probable that a liability has been incurred and the amount can be reasonably estimated. If a loss contingency is not probable or reasonably estimable, disclosure of the contingency and estimated range of loss, if determinable, is made in the financial statements when it is at least reasonably possible that a material loss could be incurred. Legal costs incurred in connection with loss contingencies are expensed as incurred.
Revenue Recognition The Company’s revenue comes from sales of rare earth products produced at Mountain Pass. The Company’s sales are primarily to an affiliate of Shenghe. The Company’s performance obligation is to produce and deliver rare earth products and the Company recognizes revenue at the point in time control of the products transfers to the customer, which is typically when the rare earth products are delivered to the agreed-upon shipping point. At that time, the customer has the ability to direct the use of and obtain substantially all of the remaining benefits from the products, and the customer bears the risk of loss. Commissions paid to distributors are deemed to be consideration payable to customers and are recorded as a reduction of the transaction prices. For sales to unrelated third parties, the transaction price is agreed to at the time the sale is entered into. For sales to Shenghe, the transaction price is based on a preliminary market price (net of taxes, tariffs, and certain other agreed charges) less applicable discounts per metric ton (“MT”), subject to an adjustment for the ultimate market price of the product realized by Shenghe upon sales to their customers. Consequently, the ultimate market prices are a form of variable consideration. Initial pricing is typically billed upon delivering the product to the agreed-upon shipping point and paid within 30 days or less. Final adjustments to prices may take longer to resolve. When the final price has not been resolved by the end of a reporting period, the Company estimates the expected sales price based on the initial price, current market pricing and known quality measurements, and further constrains such amounts to an amount that is probable not to result in a significant reversal of previously-recognized revenue. Revenue from product sales is recorded net of taxes collected from customers that are remitted to governmental authorities. When necessary and appropriate, the Company applies a portfolio approach in estimating a refund obligation.
Government Grants Government grants represent benefits provided by federal, state, or local governments that are not subject to the scope of Accounting Standards Codification (“ASC”) Topic 740, “Income Taxes” (“ASC 740”). Government grants are recognized when there is reasonable assurance the conditions of the grant will be met, and the grant will be received. When a grant is related to the purchase or construction of a long-lived asset (considered asset-based grants), the funds received are recorded as reductions of the related asset’s carrying amount, thereby reducing future depreciation expense. Alternatively, when a grant is related to an expense item (considered income-based grants), it is recognized as a reduction of expense to which the grant activity relates over the periods necessary to match the grant on a systematic basis to the costs that it is intended to compensate.
Stock-Based Compensation The cost of employee services received in exchange for an award of equity instruments is based on the grant-date fair value of the award. The fair value of Stock Awards (as defined in Note 17, “Stock-based Compensation”) is equal to the fair value of the Company’s stock on the grant date. The fair value of performance awards that include performance and/or market conditions is determined using a Monte Carlo simulation technique. The Monte Carlo simulation requires the use of inputs and assumptions such as the grant-date closing stock price, expected volatility, correlation coefficient to relevant peer groups or indices, risk-free interest rate and dividend yield.Compensation cost for Stock Awards with graded vesting schedules is recognized on a straight-line basis over the requisite service period for each separately vesting portion of the award as if the award was, in substance, multiple awards, which results in accelerated recognition of compensation cost. Compensation cost for performance awards with cliff vesting schedules is recognized on a straight-line basis over the requisite service period. Compensation cost is not adjusted based on the actual achievement of the market-based performance goals. The Company accounts for forfeitures in the period in which they occur based on actual forfeitures.
Start-up Costs Costs associated with restarting an existing facility or commissioning a new facility, circuit or process of the Company’s production, manufacturing, or separations facilities prior to the achievement of commercial production, that do not qualify for capitalization, are expensed as incurred and considered start-up costs. Such costs may include certain salaries and wages, outside services, parts, training, and utilities, among other items, used or consumed directly in these start-up activities.
Earnings Per Share Basic earnings per share (“EPS”) is computed by dividing net income by the weighted-average number of common shares outstanding during the period. Diluted EPS reflects the additional dilution for all potentially dilutive securities such as unvested Stock Awards.
Income Taxes and Valuation of Deferred Tax Assets The Company accounts for income taxes using the balance sheet method, recognizing certain temporary differences between the book basis of the liabilities and assets and the related income tax basis for such liabilities and assets. This method generates either a net deferred income tax liability or asset for the Company, as measured by the statutory tax rates in effect. The Company derives a deferred income tax expense or benefit by recording the change in either the net deferred income tax liability or asset balance for the year. The Company’s policy, if it were to have uncertain tax positions, is to recognize interest and/or penalties related to unrecognized tax benefits as part of its income tax expense.The Company’s deferred income tax assets include certain future tax benefits. The Company records a valuation allowance against any portion of those deferred income tax assets when it believes, based on the weight of available evidence, it is more likely than not that some portion or all of the deferred income tax asset will not be realized. The Company reviews the likelihood that the benefit of the deferred tax assets will be realized and the need for valuation allowances on a quarterly basis, or more frequently if events indicate that a review is required.
Certain categories of evidence carry more weight in the analysis than others based upon the extent to which the evidence may be objectively verified. The Company looks to the nature and severity of cumulative pretax losses (if any) in the current three-year period ending on the evaluation date, recent pretax losses and/or expectations of future pretax losses. Other factors considered in the determination of the probability of the realization of the deferred tax assets include, but are not limited to: earnings history; projected future financial and taxable income based upon existing reserves and long-term estimates of commodity prices; the duration of statutory carry forward periods; prudent and feasible tax planning strategies readily available that may alter the timing of reversal of the temporary difference; nature of temporary differences and predictability of reversal patterns of existing temporary differences; and the sensitivity of future forecasted results to commodity prices and other factors.
Concluding that a valuation allowance is not required is difficult when there is significant negative evidence which is objective and verifiable, such as cumulative losses in recent years. However, recent cumulative losses are not solely determinative of the need for a valuation allowance. The Company also considers all other available positive and negative evidence in its analysis.
Recently Issued Accounting Pronouncements During the year ended December 31, 2023, there were no accounting pronouncements adopted by the Company that had a material impact on the Company’s Consolidated Financial Statements.
In November 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2023-07, “Improvements to Reportable Segment Disclosures” (“ASU 2023-07”), which expands public entities’ segment disclosures by requiring disclosure of significant segment expenses that are regularly provided to the CODM and included within each reported measure of segment profit or loss, an amount and description of its composition for other segment items, and interim disclosures of a reportable segment’s profit or loss and assets. All disclosure requirements under ASU 2023-07 are also required for public entities with a single reportable segment. ASU 2023-07 is effective for the Company’s fiscal years beginning after December 15, 2023, and interim periods within fiscal years beginning after December 15, 2024, with early adoption permitted, and should be applied on a retrospective basis. The Company is currently evaluating the effect of adopting ASU 2023-07 on its disclosures.
In December 2023, the FASB issued ASU No. 2023-09, “Improvements to Income Tax Disclosures” (“ASU 2023-09”), which enhances public entities’ existing income tax disclosures to better assess how an entity’s operations, related tax risks, tax planning and operational opportunities affect its tax rate and prospects for future cash flows. ASU 2023-09 requires public entities to annually disclose specific categories in the rate reconciliation table of the income tax footnote and provide additional information for reconciling items that meet a quantitative threshold. ASU 2023-09 is effective for the Company’s annual periods beginning after December 15, 2024, with early adoption permitted. The Company is currently evaluating the effect of adopting ASU 2023-09 on its disclosures.
Reclassifications Certain amounts in prior periods have been reclassified to conform to the current year presentation.
v3.24.0.1
SIGNIFICANT ACCOUNTING POLICIES (Tables)
 12 Months Ended
Dec. 31, 2023
Accounting Policies [Abstract]  
Schedule of Estimated Useful Lives Depreciation on property, plant and equipment is recognized on a straight-line basis over their estimated useful lives, as follows:
Years
Land improvements
10-25
Buildings and building improvements
10-40
Machinery and equipment
3-20
The Company’s property, plant and equipment consisted of the following:
December 31,
(in thousands)20232022
Land and land improvements$27,091 $16,102 
Buildings and building improvements92,203 15,111 
Machinery and equipment503,145 186,388 
Assets under construction211,848 338,482 
Mineral rights438,395 438,395 
Property, plant and equipment, gross1,272,682 994,478 
Less: Accumulated depreciation and depletion(114,628)(58,735)
Property, plant and equipment, net$1,158,054 $935,743 
The Company’s depreciation and depletion expense were as follows:
For the year ended December 31,
(in thousands)202320222021
Depreciation expense$43,998 $5,808 $6,825 
Depletion expense(1)
$11,067 $12,209 $17,200 
(1)At the beginning of the fourth quarter of 2021, as a result of an updated life of mine, the Company revised its estimate of the remaining useful life of the mineral rights to approximately 35 years from approximately 23 years.
v3.24.0.1
CASH, CASH EQUIVALENTS AND INVESTMENTS (Tables)
 12 Months Ended
Dec. 31, 2023
Investments, Debt and Equity Securities [Abstract]  
Schedule of Available-for-Sale Debt Securities
The following table presents the Company’s cash, cash equivalents and short-term investments:
December 31, 2023December 31, 2022
(in thousands)Amortized Cost BasisUnrealized GainsUnrealized LossesEstimated Fair ValueAmortized Cost BasisUnrealized GainsUnrealized LossesEstimated Fair Value
Cash:
Demand deposits$2,795 $— $— $2,795 $7,373 $— $— $7,373 
Cash equivalents:
Money market funds61,166 — — 61,166 64,855 — — 64,855 
U.S. agency securities— — — — 63,605 1 (2)63,604 
U.S. Treasury securities92,113 14 — 92,127 795 — — 795 
Commercial paper
93,447 15 — 93,462 — — — — 
Certificates of deposit
13,799 2 — 13,801 — — — — 
Total cash equivalents260,525 31 — 260,556 129,255 1 (2)129,254 
Total cash and equivalents263,320 31 — 263,351 136,628 1 (2)136,627 
Short-term investments:
U.S. agency securities118,370 — (78)118,292 979,878 361 (17)980,222 
U.S. Treasury securities615,962 249 (10)616,201 65,586 1 (91)65,496 
Total short-term investments734,332 249 (88)734,493 1,045,464 362 (108)1,045,718 
Total cash, cash equivalents and short-term investments$997,652 $280 $(88)$997,844 $1,182,092 $363 $(110)$1,182,345 
Schedule of Cash and Cash Equivalents
The following table presents the Company’s cash, cash equivalents and short-term investments:
December 31, 2023December 31, 2022
(in thousands)Amortized Cost BasisUnrealized GainsUnrealized LossesEstimated Fair ValueAmortized Cost BasisUnrealized GainsUnrealized LossesEstimated Fair Value
Cash:
Demand deposits$2,795 $— $— $2,795 $7,373 $— $— $7,373 
Cash equivalents:
Money market funds61,166 — — 61,166 64,855 — — 64,855 
U.S. agency securities— — — — 63,605 1 (2)63,604 
U.S. Treasury securities92,113 14 — 92,127 795 — — 795 
Commercial paper
93,447 15 — 93,462 — — — — 
Certificates of deposit
13,799 2 — 13,801 — — — — 
Total cash equivalents260,525 31 — 260,556 129,255 1 (2)129,254 
Total cash and equivalents263,320 31 — 263,351 136,628 1 (2)136,627 
Short-term investments:
U.S. agency securities118,370 — (78)118,292 979,878 361 (17)980,222 
U.S. Treasury securities615,962 249 (10)616,201 65,586 1 (91)65,496 
Total short-term investments734,332 249 (88)734,493 1,045,464 362 (108)1,045,718 
Total cash, cash equivalents and short-term investments$997,652 $280 $(88)$997,844 $1,182,092 $363 $(110)$1,182,345 
Schedule of Interest and Investment Income
The Company recognized the following income and expense amounts, all of which are included in “Other income, net” within the Company’s Consolidated Statements of Operations:
For the year ended December 31,
(in thousands)202320222021
Gross realized gains
$575 $258 $— 
Gross realized losses
$203 $573 $— 
Interest and investment income(1)
$55,637 $19,774 $— 
Schedule of Investments Classified by Contractual Maturity Date
As of December 31, 2023, the fair values of available-for-sale investments, by remaining contractual maturity, were as follows:
(in thousands)
Due within one year$911,096 
Due after one year through two years22,787 
Total$933,883 
v3.24.0.1
INVENTORIES (Tables)
 12 Months Ended
Dec. 31, 2023
Inventory Disclosure [Abstract]  
Current Inventories
The Company’s inventories consisted of the following:
December 31,
(in thousands)20232022
Raw materials and supplies, including spare parts(1)
$42,371 $28,590 
Mined ore stockpiles28,507 25,502 
Work in process
15,019 1,710 
Finished goods
9,285 1,752 
Total current inventories95,182 57,554 
Add: Non-current portion(2)
13,350 5,744 
Total inventories$108,532 $63,298 
(1)Includes raw materials to support activities pertaining to the Company’s rare earth metal, alloy and magnet manufacturing capabilities.
(2)Represents stockpiled ore that is not expected to be processed within the next 12 months as well as certain raw materials that are not expected to be consumed within the next 12 months. The stockpiled ore amounts as of December 31, 2023 and 2022, were $9.1 million and $5.7 million, respectively.
Noncurrent Inventories
The Company’s inventories consisted of the following:
December 31,
(in thousands)20232022
Raw materials and supplies, including spare parts(1)
$42,371 $28,590 
Mined ore stockpiles28,507 25,502 
Work in process
15,019 1,710 
Finished goods
9,285 1,752 
Total current inventories95,182 57,554 
Add: Non-current portion(2)
13,350 5,744 
Total inventories$108,532 $63,298 
(1)Includes raw materials to support activities pertaining to the Company’s rare earth metal, alloy and magnet manufacturing capabilities.
(2)Represents stockpiled ore that is not expected to be processed within the next 12 months as well as certain raw materials that are not expected to be consumed within the next 12 months. The stockpiled ore amounts as of December 31, 2023 and 2022, were $9.1 million and $5.7 million, respectively.
v3.24.0.1
PROPERTY, PLANT AND EQUIPMENT (Tables)
 12 Months Ended
Dec. 31, 2023
Property, Plant and Equipment [Abstract]  
Property, plant and equipment Depreciation on property, plant and equipment is recognized on a straight-line basis over their estimated useful lives, as follows:
Years
Land improvements
10-25
Buildings and building improvements
10-40
Machinery and equipment
3-20
The Company’s property, plant and equipment consisted of the following:
December 31,
(in thousands)20232022
Land and land improvements$27,091 $16,102 
Buildings and building improvements92,203 15,111 
Machinery and equipment503,145 186,388 
Assets under construction211,848 338,482 
Mineral rights438,395 438,395 
Property, plant and equipment, gross1,272,682 994,478 
Less: Accumulated depreciation and depletion(114,628)(58,735)
Property, plant and equipment, net$1,158,054 $935,743 
The Company’s depreciation and depletion expense were as follows:
For the year ended December 31,
(in thousands)202320222021
Depreciation expense$43,998 $5,808 $6,825 
Depletion expense(1)
$11,067 $12,209 $17,200 
(1)At the beginning of the fourth quarter of 2021, as a result of an updated life of mine, the Company revised its estimate of the remaining useful life of the mineral rights to approximately 35 years from approximately 23 years.
v3.24.0.1
INTANGIBLE ASSETS (Tables)
 12 Months Ended
Dec. 31, 2023
Goodwill and Intangible Assets Disclosure [Abstract]  
Schedule of Finite-Lived Intangible Assets
The Company’s intangible assets were as follows:
December 31,
(in thousands)20232022
Intangible assets with indefinite lives:
Emissions allowances$316 $89 
Intangible assets with definite lives:
Patent and intellectual property license8,963 — 
Less: Accumulated amortization (398)— 
Patent and intellectual property license, net8,565 — 
Intangible assets, net
$8,881 $89 
Schedule of Indefinite-Lived Intangible Assets
The Company’s intangible assets were as follows:
December 31,
(in thousands)20232022
Intangible assets with indefinite lives:
Emissions allowances$316 $89 
Intangible assets with definite lives:
Patent and intellectual property license8,963 — 
Less: Accumulated amortization (398)— 
Patent and intellectual property license, net8,565 — 
Intangible assets, net
$8,881 $89 
Schedule of Future Amortization Expense
The following table presents the estimated amortization expense based on amortizing intangible assets as of December 31, 2023:
(in thousands)
Period:
2024$1,195 
20251,195 
20261,195 
20271,195 
20281,195 
Thereafter2,590 
Total$8,565 
v3.24.0.1
ASSET RETIREMENT AND ENVIRONMENTAL OBLIGATIONS (Tables)
 12 Months Ended
Dec. 31, 2023
Asset Retirement Obligation And Environmental Remediation Obligations [Abstract]  
Schedule of Change in Asset Retirement Obligation
The following is a summary of the Company’s ARO:
December 31,
(in thousands)20232022
Beginning balance$5,475 $17,757 
Obligations settled(180)(144)
Accretion expense407 976 
Revision in estimated cash flows
— (13,114)
Ending balance$5,702 $5,475 
Schedule Of Environmental Remediation Costs
As of December 31, 2023, the total environmental costs were as follows (in thousands):
Year ending December 31,
2024$536 
2025552 
2026569 
2027587 
2028605 
Thereafter23,806 
Total26,655 
Effect of discounting(9,574)
Total environmental obligations$17,081 
v3.24.0.1
ACCRUED LIABILITIES (Tables)
 12 Months Ended
Dec. 31, 2023
Payables and Accruals [Abstract]  
Schedule of Accrued Liabilities
The Company’s accrued liabilities consisted of the following:
December 31,
(in thousands)20232022
Accrued payroll and related
$14,499 $10,909 
Accrued construction costs
46,976 39,226 
Accrued taxes
3,373 281 
Other accrued liabilities
9,091 6,523 
Accrued liabilities
$73,939 $56,939 
v3.24.0.1
DEBT OBLIGATIONS (Tables)
 12 Months Ended
Dec. 31, 2023
Debt Disclosure [Abstract]  
Schedule of debt obligations
The Company’s long-term debt was as follows:
December 31,
(in thousands)20232022
Convertible Notes due 2026$690,000 $690,000 
Less: Unamortized debt issuance costs(8,020)(11,556)
Long-term debt, net
$681,980 $678,444 
The current and non-current portions of the equipment notes, which are included within the Consolidated Balance Sheets in “Other current liabilities” and “Other non-current liabilities,” respectively, were as follows:
December 31,
(in thousands)20232022
Equipment notes
Current$2,106 $2,392 
Non-current2,637 4,743 
$4,743 $7,135 
Schedule of interest expense
Interest expense related to the Convertible Notes was as follows:
For the year ended December 31,
(in thousands)202320222021
Coupon interest$1,725 $1,725 $1,318 
Amortization of debt issuance costs3,536 3,517 2,675 
Convertible Notes interest expense$5,261 $5,242 $3,993 
Interest expense, net, was as follows:
For the year ended December 31,
(in thousands)202320222021
Interest expense$5,580 $6,146 $9,168 
Interest capitalized to property, plant and equipment, net(326)(360)(264)
Interest expense, net$5,254 $5,786 $8,904 
Schedule of debt maturities
The following is a schedule of debt repayments as of December 31, 2023:
(in thousands)Convertible NotesEquipment Notes
Year ending December 31,
2024$— $2,106 
2025— 2,098 
2026690,000 539 
2027— — 
2028— — 
Thereafter— — 
Total minimum payments$690,000 $4,743 
v3.24.0.1
LEASES (Tables)
 12 Months Ended
Dec. 31, 2023
Leases [Abstract]  
Schedule of lease cost and terms and discount rates
Total lease cost included the following components:
Location on Consolidated Statements of OperationsFor the year ended December 31,
(in thousands)202320222021
Operating lease cost
Primarily Selling, general and administrative
$1,328 $424 $780 
Finance lease cost
Amortization of right-of-use assetsDepreciation, depletion and amortization246 339 357 
Interest on lease liabilitiesInterest expense, net32 44 60 
278 383 417 
Short-term lease cost
Primarily Cost of sales (excluding depreciation, depletion and amortization) (including related party)
2,134 1,509 1,163 
$3,740 $2,316 $2,360 
Information related to lease terms and discount rates was as follows:
December 31,
20232022
Weighted-average remaining lease term:
Operating leases6.6 years1.2 years
Finance leases4.4 years1.8 years
Weighted-average discount rate:
Operating leases6.9 %3.1 %
Finance leases6.0 %6.3 %
Maturities of operating lease liability
As of December 31, 2023, the maturities of the Company’s operating and finance lease liabilities were as follows:
(in thousands)Operating LeasesFinance Leases
Period:
2024$1,452 $228 
20251,472 179 
20261,362 59 
20271,370 54 
20281,403 54 
Thereafter2,663 106 
Total lease payments9,722 680 
Less: Imputed interest(1,934)(97)
Total$7,788 $583 
Maturities of finance lease liability
As of December 31, 2023, the maturities of the Company’s operating and finance lease liabilities were as follows:
(in thousands)Operating LeasesFinance Leases
Period:
2024$1,452 $228 
20251,472 179 
20261,362 59 
20271,370 54 
20281,403 54 
Thereafter2,663 106 
Total lease payments9,722 680 
Less: Imputed interest(1,934)(97)
Total$7,788 $583 
Supplemental disclosure related to operating and finance leases
Supplemental disclosure for the Consolidated Balance Sheets related to the Company’s operating and finance leases is as follows:
Location on Consolidated Balance Sheets
December 31,
(in thousands)20232022
Operating leases:
Right-of-use assetsOperating lease right-of-use assets$10,065 $99 
Operating lease liability, currentOther current liabilities$959 $84 
Operating lease liability, non-current
Operating lease liabilities
6,829 15 
Total operating lease liabilities$7,788 $99 
Finance leases:
Right-of-use assetsOther non-current assets$591 $451 
Finance lease liability, currentOther current liabilities$195 $354 
Finance lease liability, non-currentOther non-current liabilities388 242 
Total finance lease liabilities$583 $596 
v3.24.0.1
INCOME TAXES (Tables)
 12 Months Ended
Dec. 31, 2023
Income Tax Disclosure [Abstract]  
Schedule of Components of Income Tax Benefit (Expense)
Income tax expense consisted of the following:
For the year ended December 31,
(in thousands)202320222021
Current:
Federal$(178)$(24,382)$(4,818)
State(135)(9,977)(2,915)
Total current(313)(34,359)(7,733)
Deferred:
Federal(11,334)(19,236)(15,851)
State2,879 1,447 (1,574)
Total deferred(8,455)(17,789)(17,425)
Total tax expense
$(8,768)$(52,148)$(25,158)
Schedule of Loss Before Income Taxes, By Tax Jurisdiction
Income before income taxes, by tax jurisdiction, was as follows:
For the year ended December 31,
(in thousands)202320222021
United States$33,075 $341,152 $160,195 
Schedule of Effective Income Tax Rate Reconciliation
Income taxes differed from the amounts computed by applying the U.S. federal income tax rate of 21% to pretax income as a result of the following:
For the year ended December 31,
202320222021
(in thousands, except tax rates)PercentAmountPercentAmountPercentAmount
Computed income tax expense at the statutory rate
21.0 %$(6,946)21.0 %$(71,642)21.0 %$(33,641)
Changes resulting from:
State and local income taxes, net of federal benefits2.6 %(867)3.3 %(11,395)2.7 %(4,288)
Limitation on officer’s compensation11.0 %(3,640)2.3 %(8,067)1.7 %(2,638)
Depletion in excess of basis— %— (4.5)%15,248 (6.1)%9,663 
Paycheck Protection Loan forgiveness— %— — %— (0.5)%714 
Foreign-derived intangible income— %— (4.0)%13,676 (1.8)%2,886 
California Competes Tax Credit, net of federal detriment(11.3)%3,753 (0.9)%3,160 (1.2)%1,975 
Excess tax benefits (expense) on stock-based compensation
0.6 %(190)(1.0)%3,575 (0.6)%974 
Valuation allowance4.1 %(1,360)(0.8)%2,845 0.5 %(821)
Section 45X Advanced Manufacturing Credit
(0.1)%38 — %— — %— 
State rate change and other state adjustments
(1.6)%514 — %— — %— 
Other, net0.2 %(70)(0.1)%452 — %18 
Total effective tax rate and income tax expense
26.5 %$(8,768)15.3 %$(52,148)15.7 %$(25,158)
Schedule of Deferred Tax Assets and Liabilities
The tax effects of temporary differences that gave rise to significant portions of the deferred income tax assets and deferred income tax liabilities were as follows:
December 31,
(in thousands)20232022
Deferred tax assets:
Asset retirement and environmental obligations$5,640 $5,643 
Net operating losses25,107 — 
Inventories15,310 12,448 
Research and experimental costs960 691 
Stock-based compensation5,065 3,785 
Organization costs688 776 
Lease liabilities
2,084 173 
Credits3,057 346 
Other439 178 
Gross deferred tax assets58,350 24,040 
Less: Valuation allowance(1,706)(346)
Net deferred tax assets56,644 23,694 
Deferred tax liabilities:
Property, plant and equipment(83,834)(36,481)
Prepaid expenses(520)(1,567)
ROU assets
(2,638)(138)
Deferred revenue(3,270)(6,604)
Mineral rights(97,127)(101,195)
Other(48)(62)
Total deferred tax liabilities(187,437)(146,047)
Non-current deferred tax liabilities, net$(130,793)$(122,353)
v3.24.0.1
REVENUE RECOGNITION (Tables)
 12 Months Ended
Dec. 31, 2023
Revenue from Contract with Customer [Abstract]  
Disaggregation of Revenue
The following table disaggregates the Company’s revenue from contracts with customers by type of good sold, which are transferred to customers at a point in time:
For the year ended December 31,
(in thousands)
202320222021
Rare earth concentrate
$252,468 $517,267 $328,563 
NdPr oxide and metal695 — — 
Other rare earth products
282 10,243 3,389 
Total revenue$253,445 $527,510 $331,952 
v3.24.0.1
STOCK-BASED COMPENSATION (Tables)
 12 Months Ended
Dec. 31, 2023
Share-Based Payment Arrangement [Abstract]  
Schedule of Stock Awards Activity
The following table contains information on the Company’s performance awards:
Number of SharesWeighted-Average Grant Date Fair Value
Nonvested as of January 1, 2023— $— 
Granted62,709 $50.40 
Vested— $— 
Forfeited— $— 
Nonvested as of December 31, 202362,709 $50.40 
The following table contains information on the Company’s Stock Awards:
Number of SharesWeighted-Average Grant Date Fair Value
Nonvested as of January 1, 20232,208,163 $26.76 
Granted853,499 $24.13 
Vested(841,466)$25.80 
Forfeited(44,475)$28.34 
Nonvested as of December 31, 20232,175,721 $26.06 
The Company’s stock-based compensation and related income tax benefit were recorded as follows:
For the year ended December 31,
(in thousands)202320222021
Cost of sales (excluding depreciation, depletion and amortization) (including related party)
$3,932 $2,853 $4,294 
Selling, general and administrative20,508 28,554 18,246 
Start-up costs
723 119 — 
Advanced projects and development73 254 391 
Total stock-based compensation expense$25,236 $31,780 $22,931 
Stock-based compensation capitalized to property, plant and equipment, net$1,868 $1,286 $— 
Income tax benefit for stock-based compensation arrangements
$— $4,256 $3,185 
v3.24.0.1
FAIR VALUE MEASUREMENTS (Tables)
 12 Months Ended
Dec. 31, 2023
Fair Value Disclosures [Abstract]  
Fair Value Disclosure of Asset and Liability Not Measured at Fair Value The carrying amounts and estimated fair values by input level of the Company’s financial instruments were as follows:
December 31, 2023
(in thousands)
Carrying
Amount
Fair ValueLevel 1Level 2Level 3
Financial assets:
Cash and cash equivalents$263,351 $263,351 $263,351 $— $— 
Short-term investments$734,493 $734,493 $734,493 $— $— 
Restricted cash$1,637 $1,637 $1,637 $— $— 
Financial liabilities:
Convertible Notes$681,980 $619,496 $619,496 $— $— 
Equipment notes$4,743 $4,628 $— $4,628 $— 
December 31, 2022
(in thousands)
Carrying
Amount
Fair Value
Level 1Level 2Level 3
Financial assets:
Cash and cash equivalents$136,627 $136,627 $136,627 $— $— 
Short-term investments$1,045,718 $1,045,718 $1,045,718 $— $— 
Restricted cash$6,882 $6,882 $6,882 $— $— 
Financial liabilities:
Convertible Notes$678,444 $610,650 $610,650 $— $— 
Equipment notes$7,135 $6,807 $— $6,807 $— 
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis The carrying amounts and estimated fair values by input level of the Company’s financial instruments were as follows:
December 31, 2023
(in thousands)
Carrying
Amount
Fair ValueLevel 1Level 2Level 3
Financial assets:
Cash and cash equivalents$263,351 $263,351 $263,351 $— $— 
Short-term investments$734,493 $734,493 $734,493 $— $— 
Restricted cash$1,637 $1,637 $1,637 $— $— 
Financial liabilities:
Convertible Notes$681,980 $619,496 $619,496 $— $— 
Equipment notes$4,743 $4,628 $— $4,628 $— 
December 31, 2022
(in thousands)
Carrying
Amount
Fair Value
Level 1Level 2Level 3
Financial assets:
Cash and cash equivalents$136,627 $136,627 $136,627 $— $— 
Short-term investments$1,045,718 $1,045,718 $1,045,718 $— $— 
Restricted cash$6,882 $6,882 $6,882 $— $— 
Financial liabilities:
Convertible Notes$678,444 $610,650 $610,650 $— $— 
Equipment notes$7,135 $6,807 $— $6,807 $— 
v3.24.0.1
EARNINGS PER SHARE (Tables)
 12 Months Ended
Dec. 31, 2023
Earnings Per Share [Abstract]  
Schedule of weighted average number of shares
The following table reconciles the weighted-average common shares outstanding used in the calculation of basic EPS to the weighted-average common shares outstanding used in the calculation of diluted EPS:
For the year ended December 31,
202320222021
Weighted-average shares outstanding, basic177,181,661 176,519,203 173,469,546 
Assumed conversion of Public Warrants— — 2,840,624 
Assumed conversion of Convertible Notes— 15,584,409 11,997,860 
Assumed conversion of restricted stock609,326 921,772 1,257,360 
Assumed conversion of RSUs361,225 427,703 278,638 
Weighted-average shares outstanding, diluted178,152,212 193,453,087 189,844,028 
Schedule of potentially dilutive securities
The following table presents potentially dilutive shares that were not included in the computation of diluted EPS because to do so would have been antidilutive:
For the year ended December 31,
202320222021
Convertible Notes
15,584,409 — — 
RSUs3,184 24,442 18,322 
Total15,587,593 24,442 18,322 
Schedule of basic and diluted earnings per share
The following table presents the calculation of basic and diluted EPS for the Company’s common stock:
For the year ended December 31,
(in thousands, except share and per share data)202320222021
Calculation of basic EPS:
Net income
$24,307 $289,004 $135,037 
Weighted-average shares outstanding, basic177,181,661 176,519,203 173,469,546 
Basic EPS$0.14 $1.64 $0.78 
Calculation of diluted EPS:
Net income
$24,307 $289,004 $135,037 
Interest expense, net of tax(1):
Convertible Notes(2)
— 4,441 3,366 
Diluted income
$24,307 $293,445 $138,403 
Weighted-average shares outstanding, diluted178,152,212 193,453,087 189,844,028 
Diluted EPS$0.14 $1.52 $0.73 
(1)The years ended December 31, 2022, and 2021, were tax-effected at a rate of 15.3% and 15.7%, respectively.
(2)The Convertible Notes were antidilutive for the year ended December 31, 2023. Convertible debt becomes antidilutive whenever its interest expense (net of tax) per common share obtainable upon conversion exceeds basic EPS.
v3.24.0.1
RELATED PARTY TRANSACTIONS (Tables)
 12 Months Ended
Dec. 31, 2023
Related Party Transactions [Abstract]  
Schedule of related party revenue and cost of sales The Company’s related-party revenue and cost of sales were as follows:
For the year ended December 31,
(in thousands)202320222021
Revenue:
Rare earth concentrate$242,516 $487,006 $326,599 
Other rare earth products(1)
$— $9,740 $— 
Cost of sales (excluding depreciation, depletion and amortization)
$89,260 $88,681 $75,930 
(1)Represents sales agreements with Shenghe for non-concentrate products, including certain stockpiles of rare earth fluoride.
v3.24.0.1
SUPPLEMENTAL CASH FLOW INFORMATION (Tables)
 12 Months Ended
Dec. 31, 2023
Additional Cash Flow Elements and Supplemental Cash Flow Information [Abstract]  
Schedule of Cash Flow, Supplemental Disclosures
Supplemental cash flow information and non-cash investing and financing activities were as follows:
For the year ended December 31,
(in thousands)202320222021
Supplemental cash flow information:
Cash paid for interest$2,059 $2,096 $1,204 
Cash payments related to income taxes, net$20,105 $18,860 $4,172 
Change in construction payables and accrued construction costs
$18,086 $34,569 $14,082 
Supplemental non-cash investing and financing activities:
Common stock issued to acquire intangible asset
$8,963 $— $— 
Operating ROU assets obtained in exchange for lease liabilities
$7,690 $168 $— 
Finance ROU assets obtained in exchange for lease liabilities
$371 $42 $88 
Property, plant and equipment acquired with equipment notes$— $— $9,407 
Revenue recognized in exchange for debt principal reduction$— $13,566 $54,802 
Paycheck Protection Loan forgiveness$— $— $3,401 
Decrease in estimates of asset retirement costs$— $10,395 $8,713 
v3.24.0.1
DESCRIPTION OF BUSINESS AND BASIS OF PRESENTATION (Details)
 12 Months Ended
Dec. 31, 2023
segment
Organization, Consolidation and Presentation of Financial Statements [Abstract]  
Number of reportable segments 1
v3.24.0.1
SIGNIFICANT ACCOUNTING POLICIES - Narrative (Details) - USD ($)
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Dec. 31, 2020
Concentration Risk [Line Items]        
Interest receivable $ 900,000 $ 2,500,000    
Allowance for credit losses $ 0 $ 0    
Land improvements | Minimum        
Property, Plant and Equipment [Line Items]        
Property, plant and equipment, useful life 10 years      
Land improvements | Maximum        
Property, Plant and Equipment [Line Items]        
Property, plant and equipment, useful life 25 years      
Buildings and building improvements | Minimum        
Property, Plant and Equipment [Line Items]        
Property, plant and equipment, useful life 10 years      
Buildings and building improvements | Maximum        
Property, Plant and Equipment [Line Items]        
Property, plant and equipment, useful life 40 years      
Machinery and equipment | Minimum        
Property, Plant and Equipment [Line Items]        
Property, plant and equipment, useful life 3 years      
Machinery and equipment | Maximum        
Property, Plant and Equipment [Line Items]        
Property, plant and equipment, useful life 20 years      
Mineral rights        
Property, Plant and Equipment [Line Items]        
Property, plant and equipment, useful life 33 years   35 years 23 years
Shenghe | Product sales | Customer concentration risk | Affiliated Entity        
Concentration Risk [Line Items]        
Concentration risk percentage 90.00%      
v3.24.0.1
CASH, CASH EQUIVALENTS AND INVESTMENTS - Amortized Costs, Unrealized Gains and Losses, and Estimated Fair Value (Details) - USD ($)
$ in Thousands
Dec. 31, 2023
Dec. 31, 2022
Total cash and equivalents    
Amortized Cost Basis $ 263,320 $ 136,628
Unrealized Gains 31 1
Unrealized Losses 0 (2)
Estimated Fair Value 263,351 136,627
Short-term investments:    
Amortized Cost Basis 734,332 1,045,464
Unrealized Gains 249 362
Unrealized Losses (88) (108)
Short-term investments 734,493 1,045,718
Amortized Cost Basis 997,652 1,182,092
Unrealized Gains 280 363
Unrealized Losses (88) (110)
Total cash, cash equivalents and short-term investments 997,844 1,182,345
U.S. agency securities    
Short-term investments:    
Amortized Cost Basis 118,370 979,878
Unrealized Gains 0 361
Unrealized Losses (78) (17)
Short-term investments 118,292 980,222
U.S. Treasury securities    
Short-term investments:    
Amortized Cost Basis 615,962 65,586
Unrealized Gains 249 1
Unrealized Losses (10) (91)
Short-term investments 616,201 65,496
Demand deposits    
Total cash and equivalents    
Amortized Cost Basis 2,795 7,373
Unrealized Gains 0 0
Unrealized Losses 0 0
Estimated Fair Value 2,795 7,373
Money market funds    
Total cash and equivalents    
Amortized Cost Basis 61,166 64,855
Unrealized Gains 0 0
Unrealized Losses 0 0
Estimated Fair Value 61,166 64,855
U.S. agency securities    
Total cash and equivalents    
Amortized Cost Basis 0 63,605
Unrealized Gains 0 1
Unrealized Losses 0 (2)
Estimated Fair Value 0 63,604
U.S. Treasury securities    
Total cash and equivalents    
Amortized Cost Basis 92,113 795
Unrealized Gains 14 0
Unrealized Losses 0 0
Estimated Fair Value 92,127 795
Commercial paper    
Total cash and equivalents    
Amortized Cost Basis 93,447 0
Unrealized Gains 15 0
Unrealized Losses 0 0
Estimated Fair Value 93,462 0
Certificates of deposit    
Total cash and equivalents    
Amortized Cost Basis 13,799 0
Unrealized Gains 2 0
Unrealized Losses 0 0
Estimated Fair Value 13,801 0
Total cash equivalents    
Total cash and equivalents    
Amortized Cost Basis 260,525 129,255
Unrealized Gains 31 1
Unrealized Losses 0 (2)
Estimated Fair Value $ 260,556 $ 129,254
v3.24.0.1
CASH, CASH EQUIVALENTS AND INVESTMENTS - Debt Securities, Income and Expense (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Investments, Debt and Equity Securities [Abstract]      
Gross realized gains $ 575 $ 258 $ 0
Gross realized losses 203 573 0
Interest and investment income $ 55,637 $ 19,774 $ 0
v3.24.0.1
CASH, CASH EQUIVALENTS AND INVESTMENTS - Schedule of Investments Classified by Contractual Maturity Date (Details)
$ in Thousands
Dec. 31, 2023
USD ($)
Debt Securities, Available-for-Sale, Fair Value, Fiscal Year Maturity [Abstract]  
Due within one year $ 911,096
Due after one year through two years 22,787
Total $ 933,883
v3.24.0.1
INVENTORIES - Schedule of Inventories (Details) - USD ($)
$ in Thousands
Dec. 31, 2023
Dec. 31, 2022
Inventory Disclosure [Abstract]    
Raw materials and supplies, including spare parts $ 42,371 $ 28,590
Mined ore stockpiles 28,507 25,502
Work in process 15,019 1,710
Finished goods 9,285 1,752
Total current inventories 95,182 57,554
Add: Non-current portion 13,350 5,744
Total inventories 108,532 63,298
Non-current mined ore stockpiles $ 9,100 $ 5,700
v3.24.0.1
INVENTORIES - Narrative (Details) - USD ($)
$ in Thousands
 3 Months Ended 12 Months Ended
Dec. 31, 2023
Jun. 30, 2021
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Inventory Disclosure [Abstract]          
Write-down of inventories $ 2,300 $ 1,800 $ 2,285 $ 0 $ 1,809
v3.24.0.1
PROPERTY, PLANT AND EQUIPMENT - Schedule of Property, Plant, and Equipment (Details) - USD ($)
$ in Thousands
Dec. 31, 2023
Dec. 31, 2022
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, gross $ 1,272,682 $ 994,478
Less: Accumulated depreciation and depletion (114,628) (58,735)
Property, plant and equipment, net 1,158,054 935,743
Land and land improvements    
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, gross 27,091 16,102
Buildings and building improvements    
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, gross 92,203 15,111
Machinery and equipment    
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, gross 503,145 186,388
Assets under construction    
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, gross 211,848 338,482
Mineral rights    
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, gross $ 438,395 $ 438,395
v3.24.0.1
PROPERTY, PLANT AND EQUIPMENT - Narrative (Details)
 12 Months Ended
Dec. 31, 2023
USD ($)
Dec. 31, 2022
USD ($)
a
Dec. 31, 2021
USD ($)
Property, Plant and Equipment [Line Items]      
Capitalized expenditures $ 280,000,000 $ 361,200,000 $ 138,000,000
Decrease in property, plant and equipment   10,400,000 8,700,000
Decrease in depreciation expense   2,700,000 1,100,000
Demolition costs 5,500,000    
Asset impairment charges $ 0 0 0
Buildings and building improvements      
Property, Plant and Equipment [Line Items]      
Decrease in property, plant and equipment   600,000 2,000,000
Machinery and equipment      
Property, Plant and Equipment [Line Items]      
Decrease in property, plant and equipment   (2,700,000) 2,400,000
Assets under construction      
Property, Plant and Equipment [Line Items]      
Decrease in property, plant and equipment   $ 6,700,000 $ 3,200,000
Fort Worth, Texas      
Property, Plant and Equipment [Line Items]      
Area of real estate property | a   18  
v3.24.0.1
PROPERTY, PLANT AND EQUIPENT - Depreciation and Depletion Expense (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Dec. 31, 2020
Property, Plant and Equipment [Abstract]        
Depreciation expense $ 43,998 $ 5,808 $ 6,825  
Depletion expense $ 11,067 $ 12,209 $ 17,200  
Mineral rights        
Property, Plant and Equipment [Line Items]        
Property, plant and equipment, useful life 33 years   35 years 23 years
v3.24.0.1
EQUITY METHOD INVESTMENT - Narrative (Details) - USD ($)
$ in Thousands
 1 Months Ended 12 Months Ended
Dec. 31, 2023
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Schedule of Equity Method Investments [Line Items]        
Payment to acquire equity method investment   $ 9,673 $ 0 $ 0
Carrying amount of equity method investment $ 9,673 9,673 $ 0  
Impairment charge   $ 0    
VREX Holdco Pte. Ltd.        
Schedule of Equity Method Investments [Line Items]        
Payment to acquire equity method investment $ 9,700      
Equity interest percentage 49.00% 49.00%    
VREX Holdco Pte. Ltd. | Shenghe        
Schedule of Equity Method Investments [Line Items]        
Equity interest percentage 51.00% 51.00%    
v3.24.0.1
INTANGIBLE ASSETS - Narrative (Details) - USD ($)
$ in Thousands
 1 Months Ended 12 Months Ended
Aug. 31, 2023
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Schedule of Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]        
Consulting agreement, expected service fee $ 15,000      
Consulting agreement, expected service fee, payment period 4 years      
Amortization expense   $ 400 $ 0 $ 0
Intangible asset impairment   $ 0 $ 0 $ 0
Licensing Agreements        
Schedule of Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]        
Stock to be issued, purchase of assets (in shares) 435,729      
Common stock issued to acquire intangible assets (in shares) 152,504      
Definite-lived intangible asset $ 9,000      
Intangible asset, useful life 7 years 6 months      
Licensing Agreements | First vesting period        
Schedule of Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]        
Stock to be issued, purchase of assets (in shares) 43,573      
Licensing Agreements | Second vesting period        
Schedule of Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]        
Stock to be issued, purchase of assets (in shares) 43,573      
Licensing Agreements | Third vesting period        
Schedule of Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]        
Stock to be issued, purchase of assets (in shares) 43,573      
Licensing Agreements | Fourth vesting period        
Schedule of Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]        
Stock to be issued, purchase of assets (in shares) 152,506      
v3.24.0.1
INTANGIBLE ASSETS - Finite-Lived and Indefinite-Lived Intangible Assets (Details) - USD ($)
$ in Thousands
Dec. 31, 2023
Dec. 31, 2022
Intangible assets with indefinite lives:    
Emissions allowances $ 316 $ 89
Intangible assets with definite lives:    
Patent and intellectual property license 8,963 0
Less: Accumulated amortization (398) 0
Patent and intellectual property license, net 8,565 0
Intangible assets, net $ 8,881 $ 89
v3.24.0.1
INTANGIBLE ASSETS - Remaining Amortization Expenses (Details) - USD ($)
$ in Thousands
Dec. 31, 2023
Dec. 31, 2022
Goodwill and Intangible Assets Disclosure [Abstract]    
2024 $ 1,195  
2025 1,195  
2026 1,195  
2027 1,195  
2028 1,195  
Thereafter 2,590  
Patent and intellectual property license, net $ 8,565 $ 0
v3.24.0.1
ASSET RETIREMENT AND ENVIRONMENTAL OBLIGATIONS - Narrative (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Unusual Risk or Uncertainty [Line Items]      
Revision of estimate $ 0 $ 13,114 $ 9,800
Decrease in property, plant and equipment   10,400 8,700
Decrease in depreciation expense   2,700 $ 1,100
Asset retirement obligation, current 200 200  
Estimated undiscounted cash flows to satisfy obligation $ 50,200 50,400  
Remediation term 24 years    
Discount rate 2.93%    
Environmental obligations, undiscounted cost $ 26,655 27,200  
Environmental obligations, current $ 500 500  
Environmental Loss Contingency, Current, Statement of Financial Position [Extensible Enumeration] Other current liabilities    
Closure and reclamation obligations, financial assurances $ 45,400 $ 43,500  
Minimum      
Unusual Risk or Uncertainty [Line Items]      
Asset retirement obligations, credit-adjusted risk free rate 6.50%    
Maximum      
Unusual Risk or Uncertainty [Line Items]      
Asset retirement obligations, credit-adjusted risk free rate 12.00%    
v3.24.0.1
ASSET RETIREMENT AND ENVIRONMENTAL OBLIGATIONS - Summary of Asset Retirement Obligation (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]      
Beginning balance $ 5,702 $ 5,475 $ 17,757
Obligations settled (180) (144)  
Accretion expense 407 976  
Revision in estimated cash flows 0 (13,114) (9,800)
Ending balance $ 5,702 $ 5,475 $ 17,757
v3.24.0.1
ASSET RETIREMENT AND ENVIRONMENTAL OBLIGATIONS - Schedule of Environmental Remediation Costs (Details) - USD ($)
$ in Thousands
Dec. 31, 2023
Dec. 31, 2022
Asset Retirement Obligation And Environmental Remediation Obligations [Abstract]    
2024 $ 536  
2025 552  
2026 569  
2027 587  
2028 605  
Thereafter 23,806  
Total 26,655 $ 27,200
Effect of discounting (9,574)  
Total environmental obligations $ 17,081  
Environmental Loss Contingency, Statement of Financial Position [Extensible Enumeration] Environmental obligations  
v3.24.0.1
ACCRUED LIABILITIES (Details) - USD ($)
$ in Thousands
Dec. 31, 2023
Dec. 31, 2022
Payables and Accruals [Abstract]    
Accrued payroll and related $ 14,499 $ 10,909
Accrued construction costs 46,976 39,226
Accrued taxes 3,373 281
Other accrued liabilities 9,091 6,523
Accrued liabilities $ 73,939 $ 56,939
v3.24.0.1
DEBT OBLIGATIONS - Long-term Debt (Details) - USD ($)
$ in Thousands
Dec. 31, 2023
Dec. 31, 2022
Debt Instrument [Line Items]    
Less: Unamortized debt issuance costs $ (8,020) $ (11,556)
Long-term debt, net 681,980 678,444
Convertible Notes | Convertible Notes Due 2026    
Debt Instrument [Line Items]    
Convertible Notes due 2026 $ 690,000 $ 690,000
v3.24.0.1
DEBT OBLIGATIONS - Convertible Notes (Details) - Convertible Notes - Convertible Notes Due 2026
$ / shares in Units, $ in Millions
 12 Months Ended
Mar. 26, 2021
USD ($)
d
$ / shares
Dec. 31, 2023
shares
Dec. 31, 2021
USD ($)
Debt Instrument [Line Items]      
Amount borrowed | $ $ 690.0    
Debt instrument, interest rate, stated percentage 0.25%    
Proceeds from convertible debt | $     $ 672.3
Debt instrument, convertible, conversion price (in dollars per share) | $ / shares $ 44.28    
Debt instrument, convertible, conversion ratio 0.0225861    
Debt instrument, convertible, number of equity instruments (in shares) | shares   19,714,266  
Debt instrument, redemption price, percentage 100.00%    
Effective interest rate   0.51%  
Debt term   2 years 3 months 18 days  
Maximum      
Debt Instrument [Line Items]      
Debt instrument, convertible, conversion ratio 0.0285714    
Debt Instrument, Redemption, Period One      
Debt Instrument [Line Items]      
Debt instrument, convertible, threshold trading days | d 20    
Threshold consecutive trading days | d 30    
Debt instrument, convertible, threshold percentage of stock price trigger 130.00%    
Number of business days in which debt can be converted 5 days    
Consecutive business days 5 days    
Debt Instrument, Redemption, Period Two      
Debt Instrument [Line Items]      
Debt instrument, convertible, percentage of product of the last reported sale price of the company’s common stock and the conversion rate on each such trading day 98.00%    
v3.24.0.1
DEBT OBLIGATIONS - Interest Expense, Net (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Debt Instrument [Line Items]      
Convertible Notes interest expense $ 5,580 $ 6,146 $ 9,168
Interest capitalized to property, plant and equipment, net (326) (360) (264)
Interest expense, net 5,254 5,786 8,904
Convertible Notes Due 2026 | Convertible Notes      
Debt Instrument [Line Items]      
Coupon interest 1,725 1,725 1,318
Amortization of debt issuance costs 3,536 3,517 2,675
Convertible Notes interest expense $ 5,261 $ 5,242 $ 3,993
v3.24.0.1
DEBT OBLIGATIONS - Equipment Notes Narrative (Details) - Equipment notes
 12 Months Ended
Dec. 31, 2023
Minimum  
Debt Instrument [Line Items]  
Debt term 4 years
Interest rate 0.00%
Maximum  
Debt Instrument [Line Items]  
Debt term 5 years
Interest rate 6.50%
v3.24.0.1
DEBT OBLIGATIONS - Equipment Notes (Details) - Equipment notes - USD ($)
$ in Thousands
Dec. 31, 2023
Dec. 31, 2022
Equipment notes    
Current $ 2,106 $ 2,392
Non-current 2,637 4,743
Total equipment notes $ 4,743 $ 7,135
v3.24.0.1
DEBT OBLIGATIONS - Paycheck Protection Loan (Details) - USD ($)
$ in Thousands
 1 Months Ended 12 Months Ended
Apr. 30, 2020
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Debt Instrument [Line Items]        
Gain on forgiveness of Paycheck Protection Loan   $ 0 $ 0 $ 3,401
PPP Loan | Paycheck Protection Program Loan        
Debt Instrument [Line Items]        
Proceeds from debt issuance $ 3,400      
Gain on forgiveness of Paycheck Protection Loan       $ 3,400
v3.24.0.1
DEBT OBLIGATIONS - Debt Maturities (Details)
$ in Thousands
Dec. 31, 2023
USD ($)
Convertible Notes | Convertible Notes Due 2026  
Year ending December 31,  
2024 $ 0
2025 0
2026 690,000
2027 0
2028 0
Thereafter 0
Total minimum payments 690,000
Equipment notes  
Year ending December 31,  
2024 2,106
2025 2,098
2026 539
2027 0
2028 0
Thereafter 0
Total minimum payments $ 4,743
v3.24.0.1
LEASES - Narrative (Details)
$ in Thousands
 3 Months Ended 12 Months Ended
Jun. 30, 2023
USD ($)
renewalOption
Dec. 31, 2023
USD ($)
Dec. 31, 2022
USD ($)
Lessee, Lease, Description [Line Items]      
Operating lease liability $ 7,300 $ 7,788 $ 99
Operating lease right-of-use assets 10,300 $ 10,065 $ 99
Payments for tenant improvements $ 2,900    
Initial term 91 months    
Number of renewal options | renewalOption 1    
Renewal options term 5 years    
Annual base rent $ 1,200    
Minimum      
Lessee, Lease, Description [Line Items]      
Lease terms   1 month  
Lease renewal terms   1 year  
Maximum      
Lessee, Lease, Description [Line Items]      
Lease terms   9 years  
Lease renewal terms   5 years  
v3.24.0.1
LEASES - Lease Cost (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Leases [Abstract]      
Operating lease cost $ 1,328 $ 424 $ 780
Finance lease cost      
Amortization of right-of-use assets 246 339 357
Interest on lease liabilities 32 44 60
Finance lease cost 278 383 417
Short-term lease cost 2,134 1,509 1,163
Lease cost $ 3,740 $ 2,316 $ 2,360
v3.24.0.1
LEASES - Lease Terms and Discount Rates (Details)
Dec. 31, 2023
Dec. 31, 2022
Weighted-average remaining lease term:    
Operating leases 6 years 7 months 6 days 1 year 2 months 12 days
Finance leases 4 years 4 months 24 days 1 year 9 months 18 days
Weighted-average discount rate:    
Operating leases 6.90% 3.10%
Finance leases 6.00% 6.30%
v3.24.0.1
LEASES - Maturities of Lease Liabilities (Details) - USD ($)
$ in Thousands
Dec. 31, 2023
Jun. 30, 2023
Dec. 31, 2022
Operating Leases      
2024 $ 1,452    
2025 1,472    
2026 1,362    
2027 1,370    
2028 1,403    
Thereafter 2,663    
Total lease payments 9,722    
Less: Imputed interest (1,934)    
Total 7,788 $ 7,300 $ 99
Finance Leases      
2024 228    
2025 179    
2026 59    
2027 54    
2028 54    
Thereafter 106    
Total lease payments 680    
Less: Imputed interest (97)    
Total $ 583   $ 596
v3.24.0.1
LEASES - Supplemental Disclosure for the Consolidated Balance Sheets (Details) - USD ($)
$ in Thousands
Dec. 31, 2023
Jun. 30, 2023
Dec. 31, 2022
Operating leases      
Right-of-use assets $ 10,065 $ 10,300 $ 99
Operating lease liability, current 959   84
Operating Lease, Liability, Noncurrent 6,829   15
Total operating lease liabilities $ 7,788 $ 7,300 $ 99
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] Other current liabilities   Other current liabilities
Finance leases      
Right-of-use assets $ 591   $ 451
Finance lease liability, current 195   354
Finance lease liability, non-current 388   242
Total finance lease liabilities $ 583   $ 596
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration] Other Assets, Noncurrent   Other Assets, Noncurrent
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration] Other current liabilities   Other current liabilities
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration] Other non-current liabilities   Other non-current liabilities
v3.24.0.1
INCOME TAXES - Schedule of Income Tax Benefit (Expense) (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Current:      
Federal $ (178) $ (24,382) $ (4,818)
State (135) (9,977) (2,915)
Total current (313) (34,359) (7,733)
Deferred:      
Federal (11,334) (19,236) (15,851)
State 2,879 1,447 (1,574)
Total deferred (8,455) (17,789) (17,425)
Income tax expense $ (8,768) $ (52,148) $ (25,158)
v3.24.0.1
INCOME TAXES - Schedule of Income (Loss) Before Taxes (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Income Tax Disclosure [Abstract]      
Loss before income taxes, United States $ 33,075 $ 341,152 $ 160,195
v3.24.0.1
INCOME TAXES - Schedule of Income Tax Rate Reconciliation (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Effective Income Tax Rate Reconciliation, Percent [Abstract]      
Computed income tax expense at the statutory rate 21.00% 21.00% 21.00%
State and local income taxes, net of federal benefits 2.60% 3.30% 2.70%
Limitation on officer’s compensation 11.00% 2.30% 1.70%
Depletion in excess of basis 0.00% (4.50%) (6.10%)
Paycheck Protection Loan forgiveness 0.00% 0.00% (0.50%)
Foreign-derived intangible income 0.00% (4.00%) (1.80%)
California Competes Tax Credit, net of federal detriment (11.30%) (0.90%) (1.20%)
Excess tax benefits (expense) on stock-based compensation 0.60% (1.00%) (0.60%)
Valuation allowance 4.10% (0.80%) 0.50%
Section 45X Advanced Manufacturing Credit (0.10%) 0.00% 0.00%
State rate change and other state adjustments (1.60%) 0.00% 0.00%
Other, net 0.20% (0.10%) 0.00%
Total effective tax rate and income tax expense 26.50% 15.30% 15.70%
Effective Income Tax Rate Reconciliation, Amount [Abstract]      
Computed income tax expense at the statutory rate $ (6,946) $ (71,642) $ (33,641)
State and local income taxes, net of federal benefits (867) (11,395) (4,288)
Limitation on officer’s compensation (3,640) (8,067) (2,638)
Depletion in excess of basis 0 15,248 9,663
Paycheck Protection Loan forgiveness 0 0 714
Foreign-derived intangible income 0 13,676 2,886
California Competes Tax Credit, net of federal detriment 3,753 3,160 1,975
Excess tax benefits (expense) on stock-based compensation (190) 3,575 974
Valuation allowance (1,360) 2,845 (821)
Section 45X Advanced Manufacturing Credit (38) 0 0
State rate change and other state adjustments 514 0 0
Other, net (70) 452 18
Income tax expense $ (8,768) $ (52,148) $ (25,158)
v3.24.0.1
INCOME TAXES - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($)
$ in Thousands
Dec. 31, 2023
Dec. 31, 2022
Deferred Tax Assets, Net [Abstract]    
Asset retirement and environmental obligations $ 5,640 $ 5,643
Net operating losses 25,107 0
Inventories 15,310 12,448
Research and experimental costs 960 691
Stock-based compensation 5,065 3,785
Organization costs 688 776
Lease liabilities 2,084 173
Credits 3,057 346
Other 439 178
Gross deferred tax assets 58,350 24,040
Less: Valuation allowance (1,706) (346)
Net deferred tax assets 56,644 23,694
Deferred Tax Liabilities, Net [Abstract]    
Property, plant and equipment (83,834) (36,481)
Prepaid expenses (520) (1,567)
ROU assets (2,638) (138)
Deferred revenue (3,270) (6,604)
Mineral rights (97,127) (101,195)
Other (48) (62)
Total deferred tax liabilities (187,437) (146,047)
Non-current deferred tax liabilities, net $ (130,793) $ (122,353)
v3.24.0.1
INCOME TAXES - Additional Information (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Operating Loss Carryforwards [Line Items]      
Operating loss carryforwards $ 119,600 $ 0  
California Competes tax credit 3,753 3,160 $ 1,975
California Franchise Tax Board      
Operating Loss Carryforwards [Line Items]      
Tax credit carryforward     14,800
California Competes tax credit $ 4,800 $ 4,000 $ 2,500
v3.24.0.1
COMMITMENTS AND CONTINGENCIES (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]      
Percentage of salary deferrals matched 100.00%    
Maximum percentage of compensation matched 4.00%    
Contribution expense $ 2.0 $ 0.9 $ 0.6
v3.24.0.1
STOCKHOLDERS’ EQUITY - Narrative (Details) - $ / shares
 12 Months Ended
Dec. 31, 2021
Dec. 31, 2023
Dec. 31, 2022
May 04, 2021
Nov. 17, 2020
May 04, 2020
Class of Warrant or Right [Line Items]            
Capital stock, authorized (shares)         500,000,000  
Common stock, authorized (shares)   450,000,000 450,000,000   450,000,000  
Preferred stock, authorized (shares)   50,000,000 50,000,000   50,000,000  
Common stock, par value (usd per share)   $ 0.0001 $ 0.0001   $ 0.0001  
Preferred stock, par value (usd per share)   $ 0.0001 $ 0.0001   $ 0.0001  
Public Warrant            
Class of Warrant or Right [Line Items]            
Number of securities called by warrants (in shares)           11,499,968
Exercise price of warrants (usd per share)           $ 11.50
Redemption price per share (usd per share)       $ 0.01    
The shares surrendered per warrant for a cashless exercise of the public warrants 0.3808          
Redemption of Public Warrants (shares) 7,080,005          
Number cashless exercised (shares) 11,434,455          
Number of warrants redeemed (shares) 65,513          
Cashless Exercise Of Public Warrants            
Class of Warrant or Right [Line Items]            
The shares received per warrant for the cashless exercise of the public warrants 0.6192          
v3.24.0.1
REVENUE RECOGNITION - Disaggregation of Revenue (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Disaggregation of Revenue [Line Items]      
Total revenue $ 253,445 $ 527,510 $ 331,952
Rare earth concentrate (including related party)      
Disaggregation of Revenue [Line Items]      
Total revenue 252,468 517,267 328,563
NdPr oxide and metal      
Disaggregation of Revenue [Line Items]      
Total revenue 695 0 0
Other rare earth products (including related party)      
Disaggregation of Revenue [Line Items]      
Total revenue $ 282 $ 10,243 $ 3,389
v3.24.0.1
GOVERNMENT GRANTS - Additional Details (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Feb. 28, 2022
Nov. 30, 2020
Government Assistance [Line Items]          
Proceeds from government awards used for construction $ 2,800 $ 5,130 $ 4,382    
Government grant receivable 19,302 0      
HREE production project agreement          
Government Assistance [Line Items]          
Proceeds from government awards used for construction 2,800        
Optimization contribution       $ 35,000  
Technology investment agreement          
Government Assistance [Line Items]          
Technology investment agreement, stage II optimization contribution 100       $ 9,600
Proceeds from government awards used for construction   $ 5,100 $ 4,400    
45X Credit government grant          
Government Assistance [Line Items]          
Government grant receivable 19,300        
Deferred government grant 19,100        
Deferred government grant, current $ 1,700        
Deferred government grant, amortization period 11 years        
v3.24.0.1
STOCK-BASED COMPENSATION - Narrative (Details) - USD ($)
$ / shares in Units, $ in Millions
 12 Months Ended
Nov. 17, 2020
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Dec. 31, 2020
Nov. 30, 2020
PSUs            
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]            
Shares granted (in shares)   62,709        
Unamortized compensation cost not yet recognized   $ 2.1        
Unamortized compensation costs not yet recognized, weighted-average recognition period   2 years        
Shares vested (in shares)   0        
Weighted average grant date fair value   $ 50.40        
Restricted stock            
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]            
Shares granted (in shares)         2,013,006  
Shares vested (in shares)         200,000  
RSUs            
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]            
Shares granted (in shares)   805,322 382,742 1,026,387    
Requisite service period   4 years        
Shares vested (in shares)   67,700 36,461 80,350    
RSUs | Non-employee directors            
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]            
Shares granted (in shares)   48,177 23,975 18,394    
Shares vested (in shares)   10,691 6,881 5,810    
Stock Awards            
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]            
Shares granted (in shares)   853,499        
Unamortized compensation cost not yet recognized   $ 23.2        
Unamortized compensation costs not yet recognized, weighted-average recognition period   1 year 9 months 18 days        
Shares vested (in shares)   841,466        
Weighted average grant date fair value   $ 24.13 $ 38.52 $ 41.24    
Shares vested, fair value   $ 20.7 $ 40.0 $ 10.9    
2020 Incentive Plan            
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]            
Shares initially available for issuance (shares)           9,653,671
Annual increase percentage in shares available for issuance 2.00%          
Shares available for future grants (in shares)   5,928,540        
2023 Performance Share Plan | PSUs            
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]            
Shares granted (in shares)   62,709        
Vesting period   3 years        
Requisite service period   3 years        
2023 Performance Share Plan | PSUs | Minimum            
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]            
Vesting percentage of the awards granted (as a percent)   0.00%        
2023 Performance Share Plan | PSUs | Maximum            
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]            
Vesting percentage of the awards granted (as a percent)   200.00%        
v3.24.0.1
STOCK-BASED COMPENSATION - Schedule of Stock Awards Activity (Details) - $ / shares
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
PSUs      
Number of Shares      
Beginning balance (in shares) 0    
Granted (in shares) 62,709    
Vested (in shares) 0    
Forfeited (in shares) 0    
Ending balance (in shares) 62,709 0  
Weighted-Average Grant Date Fair Value      
Beginning balance (in USD per share) $ 0    
Granted (in USD per share) 50.40    
Vested (in USD per share) 0    
Forfeited (in USD per share) 0    
Ending balance (in USD per share) $ 50.40 $ 0  
Stock Awards      
Number of Shares      
Beginning balance (in shares) 2,208,163    
Granted (in shares) 853,499    
Vested (in shares) (841,466)    
Forfeited (in shares) (44,475)    
Ending balance (in shares) 2,175,721 2,208,163  
Weighted-Average Grant Date Fair Value      
Beginning balance (in USD per share) $ 26.76    
Granted (in USD per share) 24.13 $ 38.52 $ 41.24
Vested (in USD per share) 25.80    
Forfeited (in USD per share) 28.34    
Ending balance (in USD per share) $ 26.06 $ 26.76  
v3.24.0.1
STOCK-BASED COMPENSATION - Schedule of Stock-Based Compensation and Related Income Tax Benefit (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]      
Total stock-based compensation expense $ 25,236 $ 31,780 $ 22,931
Stock-based compensation capitalized to property, plant and equipment, net 1,868 1,286 0
Income tax benefit for stock-based compensation arrangements 0 4,256 3,185
Cost of sales (excluding depreciation, depletion and amortization) (including related party)      
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]      
Total stock-based compensation expense 3,932 2,853 4,294
Selling, general and administrative      
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]      
Total stock-based compensation expense 20,508 28,554 18,246
Start-up costs      
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]      
Total stock-based compensation expense 723 119 0
Advanced projects and development      
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]      
Total stock-based compensation expense $ 73 $ 254 $ 391
v3.24.0.1
FAIR VALUE MEASUREMENTS - Carrying Values and Estimated Fair Values (Details) - USD ($)
$ in Thousands
Dec. 31, 2023
Dec. 31, 2022
Financial assets:    
Cash and cash equivalents $ 263,351 $ 136,627
Level 1    
Financial assets:    
Cash and cash equivalents 263,351 136,627
Short-term investments 734,493 1,045,718
Restricted cash 1,637 6,882
Level 2    
Financial assets:    
Cash and cash equivalents 0 0
Short-term investments 0 0
Restricted cash 0 0
Level 3    
Financial assets:    
Cash and cash equivalents 0 0
Short-term investments 0 0
Restricted cash 0 0
Convertible Notes | Level 1    
Financial liabilities:    
Convertible Notes and equipment notes 619,496 610,650
Convertible Notes | Level 2    
Financial liabilities:    
Convertible Notes and equipment notes 0 0
Convertible Notes | Level 3    
Financial liabilities:    
Convertible Notes and equipment notes 0 0
Equipment notes | Level 1    
Financial liabilities:    
Convertible Notes and equipment notes 0 0
Equipment notes | Level 2    
Financial liabilities:    
Convertible Notes and equipment notes 4,628 6,807
Equipment notes | Level 3    
Financial liabilities:    
Convertible Notes and equipment notes 0 0
Carrying Amount    
Financial assets:    
Cash and cash equivalents 263,351 136,627
Short-term investments 734,493 1,045,718
Restricted cash 1,637 6,882
Carrying Amount | Convertible Notes    
Financial liabilities:    
Convertible Notes and equipment notes 681,980 678,444
Carrying Amount | Equipment notes    
Financial liabilities:    
Convertible Notes and equipment notes 4,743 7,135
Fair Value    
Financial assets:    
Cash and cash equivalents 263,351 136,627
Short-term investments 734,493 1,045,718
Restricted cash 1,637 6,882
Fair Value | Convertible Notes    
Financial liabilities:    
Convertible Notes and equipment notes 619,496 610,650
Fair Value | Equipment notes    
Financial liabilities:    
Convertible Notes and equipment notes $ 4,628 $ 6,807
v3.24.0.1
EARNINGS PER SHARE - Weighted Average Number of Shares Outstanding (Details) - shares
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Class of Warrant or Right [Line Items]      
Basic (in shares) 177,181,661 176,519,203 173,469,546
Assumed conversion of Public Warrants (shares) 0 0 2,840,624
Assumed conversion of Convertible Notes (shares) 0 15,584,409 11,997,860
Diluted (in shares) 178,152,212 193,453,087 189,844,028
Restricted Stock [Member]      
Class of Warrant or Right [Line Items]      
Assumed conversion of stock awards (shares) 609,326 921,772 1,257,360
RSUs      
Class of Warrant or Right [Line Items]      
Assumed conversion of stock awards (shares) 361,225 427,703 278,638
v3.24.0.1
EARNINGS PER SHARE - Potentially Dilutive Securities (Details) - shares
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Potentially dilutive shares not included in computation of diluted EPS 15,587,593 24,442 18,322
Convertible Notes Due 2026      
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Potentially dilutive shares not included in computation of diluted EPS 15,584,409 0 0
RSUs      
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]      
Potentially dilutive shares not included in computation of diluted EPS 3,184 24,442 18,322
v3.24.0.1
EARNINGS PER SHARE - Calculation of Basic and Diluted Earnings Per Share (Details) - USD ($)
$ / shares in Units, $ in Thousands
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Calculation of basic EPS:      
Net income $ 24,307 $ 289,004 $ 135,037
Basic (in shares) 177,181,661 176,519,203 173,469,546
Basic (in USD per share) $ 0.14 $ 1.64 $ 0.78
Calculation of diluted EPS:      
Interest expense on convertible debt, net of tax $ 0 $ 4,441 $ 3,366
Diluted income (loss) $ 24,307 $ 293,445 $ 138,403
Diluted (in shares) 178,152,212 193,453,087 189,844,028
Diluted (in USD per share) $ 0.14 $ 1.52 $ 0.73
Effective tax rate 26.50% 15.30% 15.70%
v3.24.0.1
RELATED PARTY TRANSACTIONS - Narrative (Details) - USD ($)
$ in Thousands
 1 Months Ended 12 Months Ended
Jan. 31, 2024
Oct. 31, 2023
Mar. 31, 2022
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Related Party Transaction [Line Items]            
Purchases from related party       $ 8,300 $ 18,500 $ 4,800
Accounts receivable       10,029 32,856  
Related Party            
Related Party Transaction [Line Items]            
Accounts receivable       9,200 $ 29,800  
Offtake Agreement            
Related Party Transaction [Line Items]            
Initial term     2 years      
Extension period     1 year      
New Offtake Agreement | Subsequent event            
Related Party Transaction [Line Items]            
Initial term 2 years          
Extension period 1 year          
VREX Tolling Agreement            
Related Party Transaction [Line Items]            
Initial term   3 years        
Extension period   3 years        
Prepayment for tolling services       $ 1,200    
v3.24.0.1
RELATED PARTY TRANSACTIONS - Related Party Revenue and Cost of Sales (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Related Party Transaction [Line Items]      
Total revenue $ 253,445 $ 527,510 $ 331,952
Cost of sales (excluding depreciation, depletion and amortization) 92,714 92,218 76,253
Related Party      
Related Party Transaction [Line Items]      
Cost of sales (excluding depreciation, depletion and amortization) 89,260 88,681 75,930
Rare earth concentrate (including related party)      
Related Party Transaction [Line Items]      
Total revenue 252,468 517,267 328,563
Rare earth concentrate (including related party) | Related Party      
Related Party Transaction [Line Items]      
Total revenue 242,516 487,006 326,599
Other rare earth products (including related party)      
Related Party Transaction [Line Items]      
Total revenue 282 10,243 3,389
Other rare earth products (including related party) | Related Party      
Related Party Transaction [Line Items]      
Total revenue $ 0 $ 9,740 $ 0
v3.24.0.1
SUPPLEMENTAL CASH FLOW INFORMATION (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2023
Dec. 31, 2022
Dec. 31, 2021
Supplemental cash flow information:      
Cash paid for interest $ 2,059 $ 2,096 $ 1,204
Cash payments related to income taxes, net 20,105 18,860 4,172
Change in construction payables and accrued construction costs 18,086 34,569 14,082
Supplemental Non-Cash Investing Activities [Abstract]      
Common stock issued to acquire intangible asset 8,963 0 0
Operating ROU assets obtained in exchange for lease liabilities 7,690 168 0
Finance ROU assets obtained in exchange for lease liabilities 371 42 88
Property, plant and equipment acquired with equipment notes 0 0 9,407
Revenue recognized in exchange for debt principal reduction 0 13,566 54,802
Paycheck Protection Loan forgiveness 0 0 3,401
Decrease in estimates of asset retirement costs $ 0 $ 10,395 $ 8,713