SECURITIES AND EXCHANGE COMMISSION	
Washington, D.C. 20549	
 	
SCHEDULE 13G/A	
 	
Under the Securities Exchange Act of 1934	
(Amendment No. 1)*	
 	
Spark Energy, Inc.	
(Name of Issuer)	
 	
Class A Common Stock, par value $0.01 per share	
(Title of Class of Securities)	
 	
846511103	
(CUSIP Number)	
 	
December 31, 2015	
(Date of Event Which Requires Filing of This Statement)	

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:	
 	
¨	Rule 13d-1(b)	
ý	Rule 13d-1(c)	
¨	Rule 13d-1(d)	
 	
(Page 1 of 7 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 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. 846511103	13G/A	 Page  2  of 7 Pages	

1	NAME OF REPORTING PERSON
Numeric Investors LLC	
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP	(a)  ¨
(b)  ¨	
3	SEC USE ONLY	
4	CITIZENSHIP OR PLACE OF ORGANIZATION
State of Delaware	
NUMBER OF
SHARES
BENEFICIALLY
OWNED BY
EACH
REPORTING
PERSON WITH:	5	SOLE VOTING POWER
0	
	6	SHARED VOTING POWER
157,117 shares of Class A Common Stock	
	7	SOLE DISPOSITIVE POWER
0	
	8	SHARED DISPOSITIVE POWER
157,117 shares of Class A Common Stock	
9	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
157,117 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)
5.07%	
12	TYPE OF REPORTING PERSON
OO	

CUSIP No. 846511103	13G/A	 Page  3  of 7 Pages	

1	NAME OF REPORTING PERSON
Man Group plc	
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP	(a)  ¨
(b)  ¨	
3	SEC USE ONLY	
4	CITIZENSHIP OR PLACE OF ORGANIZATION
United Kingdom	
NUMBER OF
SHARES
BENEFICIALLY
OWNED BY
EACH
REPORTING
PERSON WITH:	5	SOLE VOTING POWER
0	
	6	SHARED VOTING POWER
157,117 shares of Class A Common Stock	
	7	SOLE DISPOSITIVE POWER
0	
	8	SHARED DISPOSITIVE POWER
157,117 shares of Class A Common Stock	
9	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
157,117 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)
5.07%	
12	TYPE OF REPORTING PERSON
OO, HC	

 

CUSIP No. 846511103	13G/A	 Page  4  of 7 Pages	

Item 1(a).	NAME OF ISSUER	
 	 	
 	The name of the issuer is Spark Energy, Inc., a Delaware corporation (the " Company ").	
 
Item 1(b).	ADDRESS OF ISSUER'S PRINCIPAL EXECUTIVE OFFICES	
 	 	
 	The Company's principal executive offices are located at 12140 Wickchester Ln, Ste 100., Suite 100, Houston, Texas 77079.	
 
Item 2(a).	NAME OF PERSON FILING	
 	 	
 	This statement is filed by the entities and persons listed below, who are collectively referred to herein as the " Reporting Persons " with respect to the Class A Common Stock (as defined in Item 2(d) below):	
 	 	
 	Investment Manager:	
 	 	
 	(i)	Numeric Investors LLC (the " Investment Manager "), with respect to the Class A Common Stock held by certain funds and/or managed accounts to which the Investment Manager serves as investment manager (collectively, the " Numeric Funds ").	
 	 	 	
 	Parent Company:	
 	 	 	
 	(ii)	Man Group plc (the " Parent Company "), which indirectly, through various intermediate entities, controls the Investment Manager, with respect to the Class A Common Stock held by each of the Numeric Funds.	
 	 	 	
Item 2(b).	ADDRESS OF PRINCIPAL BUSINESS OFFICE OR, IF NONE, RESIDENCE:	
Item 2(c).	CITIZENSHIP:	
 	 	
 	This statement is filed by:	
 	 	
 	(i)	Numeric Investors LLC
470 Atlantic Avenue,6th Floor
Boston, MA 02210
Citizenship: State of Delaware	
 	 	 	
 	(ii)	Man Group Plc
Riverbank House
2 Swan Lane
London EC4R 3AD
United Kingdom
Citizenship: United Kingdom	
 
Item 2(d).	TITLE OF CLASS OF SECURITIES:	
 	 	
 	Class A Common Stock, par value $0.01 per share (the " Class A Common Stock ").	
 
Item 2(e).	CUSIP NUMBER:	
 	 	
 	846511103	

CUSIP No. 846511103	13G/A	 Page  5  of 7 Pages	

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,	
 	(d)	¨	Investment Company registered under Section 8 of the Investment Company Act of 1940,	
 	(e)	¨	An investment adviser in accordance with Rule 13d-1(b)(1)(ii)(E);	
 	(f)	¨	Employee Benefit Plan or Endowment Fund in accordance with Rule 13d-1(b)(1)(ii)(F),	
 	(g)	¨	Parent Holding Company or control person in accordance with Rule 13d-1(b)(1)(ii)(G),	
 	(h)	¨	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 each Reporting Person hereto and is incorporated herein by reference for each such Reporting Person.  The percentage set forth in Row (11) of the cover page for each Reporting Person is based on the 3,097,173 shares of Class A Common Stock outstanding as of November 10, 2015, as reported in the Company's Quarterly Report on Form 10-Q for the quarterly period ended September 30, 2015 filed with the Securities and Exchange Commission on November 12, 2015.	
 	 	
 	The Investment Manager, which serves as the investment manager to each of the Numeric Funds, may be deemed to be the beneficial owner of all of the Class A Common Stock owned by the Numeric Funds.  The Parent Company, which indirectly, through various intermediate entities, controls the Investment Manager, may be deemed to be the beneficial owner of all the Class A Common Stock owned by the Numeric Funds. The Parent Company hereby disclaims any beneficial ownership of any such Class A Common Stock.	

CUSIP No. 846511103	13G/A	 Page  6  of 7 Pages	

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.	

Item 7.	IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY WHICH ACQUIRED THE SECURITY BEING REPORTED ON BY THE PARENT HOLDING COMPANY.	
 	 	
 	Not applicable.	

Item 8.	IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF THE GROUP.	
 	 	
 	Not applicable.	

Item 9.	NOTICE OF DISSOLUTION OF GROUP.	
 	 	
 	Not applicable.	

Item 10.	CERTIFICATION.	
 
 	Each of the Reporting Persons hereby makes the following certification:	
 	 	
 	By signing below each Reporting Person certifies that, to the best of its knowledge and belief, the securities referred to above 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. 846511103	13G/A	 Page  7  of 7 Pages	

SIGNATURES
After reasonable inquiry and to the best of its knowledge and belief, each of the undersigned certifies that the information set forth in this statement is true, complete and correct.
DATE: February 11, 2016
 
NUMERIC INVESTORS LLC	 	 	

By:  /s/ Dunyelle Rosen	 	 	
Name: /s/ Dunyelle Rosen	 	 	
Title: Chief Compliance Officer	 	 	
 	 	 	
MAN GROUP PLC	 	 	

By:  /s/ Michelle Robyn Grew	 	 	
Name: Michelle Robyn Grew	 	 	
Title: Global Head of Legal and Compliance