SECURITIES AND EXCHANGE COMMISSION	
Washington, D.C. 20549	
 	
SCHEDULE 13G	
 	
Under the Securities Exchange Act of 1934	
(Amendment No. )*	
 	
Mosaic Acquisition Corp.	
(Name of Issuer)	
 	
Class A Common Stock, par value $0.0001 per share	
(Title of Class of Securities)	
 	
G62848109**	
(CUSIP Number)	
 	
December 31, 2017	
(Date of Event Which Requires Filing of This Statement)	

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:	
 	
ý	Rule 13d-1(b)	
¨	Rule 13d-1(c)	
¨	Rule 13d-1(d)	
 	
(Page 1 of 6 Pages)	
 
______________________________
*The remainder of this cover page shall be filled out for a reporting person's initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page.
**The Class A Common Stock has no CUSIP number. The CINS number for the Class A Common Stock is G62848109.
The information required in the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

CUSIP No. G62848109	13G/A	Page  2  of 6 Pages	
 
1	NAME OF REPORTING PERSON
Fir Tree Capital Management LP	
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP	(a) ¨
(b) ¨	
3	SEC USE ONLY	
4	CITIZENSHIP OR PLACE OF ORGANIZATION
Delaware	
NUMBER OF
SHARES
BENEFICIALLY
OWNED BY
EACH
REPORTING
PERSON WITH:	5	SOLE VOTING POWER
1,800,000 shares of Class A Common Stock	
	6	SHARED VOTING POWER
0	
	7	SOLE DISPOSITIVE POWER
1,800,000 shares of Class A Common Stock	
	8	SHARED DISPOSITIVE POWER
0	
9	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
1,800,000 shares of Class A Common Stock	
10	CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES	¨	
11	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)
5.22%	
12	TYPE OF REPORTING PERSON
IA, PN	

 

CUSIP No. G62848109	13G/A	Page  3  of 6 Pages	
 
Item 1(a).	NAME OF ISSUER	
 	 	
 	Mosaic Acquisition Corp. (the " Issuer ")	
 
Item 1(b).	ADDRESS OF ISSUER'S PRINCIPAL EXECUTIVE OFFICES	
 	 	
 	375 Park Avenue Suite 2607
New York, New York 10152	
 
Item 2(a).	NAME OF PERSON FILING	
 	 	
 	This Schedule 13G is being filed on behalf of Fir Tree Capital Management LP, a Delaware limited partnership (" Fir Tree "), relating to Class A Common Stock, par value $0.0001 per share (the " Class A Common Stock "), issued by the Issuer, purchased by certain private-pooled investment vehicles for which Fir Tree serves as the investment manager (the " Funds ").	
 	 	
 	Fir Tree is the investment manager of the Funds, and has been granted investment discretion over portfolio investments, including the Class A Common Stock held by the Funds.	
 
Item 2(b).	ADDRESS OF PRINCIPAL BUSINESS OFFICE OR, IF NONE, RESIDENCE	
 	 	
 	The address of the principal business office of Fir Tree is:	
 	 	
 	Fir Tree Capital Management LP
55 West 46th Street, 29th Floor
New York, New York 10036	
 
Item 2(c).	CITIZENSHIP	
 	 	
 	Fir Tree is a Delaware limited partnership.	
 
Item 2(d).	TITLE OF CLASS OF SECURITIES	
 	 	
 	Class A Common Stock, par value $0.0001 per share	
 
Item 2(e).	CUSIP NUMBER	
 	 	
 	The Class A Common Stock has no CUSIP number. The CINS number for the Class A Common Stock is G62848109.	
 
Item 3.	IF THIS STATEMENT IS FILED PURSUANT TO Rules 13d-1(b), OR 13d-2(b) OR (c), CHECK WHETHER THE PERSON FILING IS A:	
 	 	
 	(a)	¨	Broker or dealer registered under Section 15 of the Act;	
 	(b)	¨	Bank as defined in Section 3(a)(6) of the Act;	
 	(c)	¨	Insurance company as defined in Section 3(a)(19) of the Act;	

CUSIP No. G62848109	13G/A	Page  4  of 6 Pages	

 	(d)	¨	Investment company registered under Section 8 of the Investment Company Act of 1940;	
 	(e)	ý	An investment adviser in accordance with Rule 13d-1(b)(1)(ii)(E);	
 	(f)	¨	An employee benefit plan or endowment fund in accordance with Rule 13d-1(b)(1)(ii)(F);
 	
 	(g)	¨	A parent holding company or control person in accordance with Rule 13d-1(b)(1)(ii)(G);
 	
 	(h)	¨	A savings association as defined in Section 3(b) of the Federal Deposit Insurance Act;
 	
 	(i)	¨	A church plan that is excluded from the definition of an investment company under Section 3(c)(14) of the Investment Company Act;
 	
 	(j)	¨	A non-U.S. institution in accordance with Rule 13d-1(b)(1)(ii)(J);	
 	(k)	¨	Group, in accordance with Rule 13d-1(b)(1)(ii)(K).	
 	If filing as a non-U.S. institution in accordance with Rule 13d-1(b)(1)(ii)(J), please	
 	specify the type of institution:	 	 	

Item 4.	OWNERSHIP	
 	 	
 	The information required by Items 4(a) – (c) is set forth in Rows (5) – (11) of the cover page for the Reporting Person and is incorporated herein by reference.  	
 	 	
 	The percentage set forth in Row (11) of the cover page for the Reporting Person is based on the 34,500,000 shares of Class A Common Stock outstanding as of December 1, 2017, as reported in the Issuer's Quarterly Report on Form 10-Q for the quarterly period ended September 30, 2017 filed with the Securities and Exchange Commission on December 1, 2017.	
 
Item 5.	OWNERSHIP OF FIVE PERCENT OR LESS OF A CLASS	
 	 	
 	Not applicable.	
  
Item 6.	OWNERSHIP OF MORE THAN FIVE PERCENT ON BEHALF OF ANOTHER PERSON	
 	 	
 	See Item 2(a).  	
 
Item 7.	IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY WHICH ACQUIRED THE SECURITY BEING REPORTED ON BY THE PARENT HOLDING COMPANY OR CONTROL PERSON	
 	 	
 	Not applicable.	

CUSIP No. G62848109	13G/A	Page  5  of 6 Pages	

Item 8.	IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF THE GROUP	
 	 	
 	Not applicable.	
 
Item 9.	NOTICE OF DISSOLUTION OF GROUP	
 	 	
 	Not applicable.	
 
Item 10.	CERTIFICATION	 	
 	 	
 	By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect.	

 

CUSIP No. G62848109	13G/A	Page  6  of 6 Pages	
 
SIGNATURES
After reasonable inquiry and to the best of his or its knowledge and belief, each of the undersigned certifies that the information set forth in this statement is true, complete and correct.
DATE: February 14, 2018
 
FIR TREE CAPITAL MANAGEMENT LP	 	 	

/s/ Brian Meyer	 	 	
Name: Brian Meyer	 	 	
Title: General Counsel