Sec Form 4 Filing - VANTAGEPOINT VENTURE ASSOCIATES IV LLC @ GAIN Capital Holdings, Inc. - 2017-03-15

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person VANTAGEPOINT VENTURE ASSOCIATES IV LLC 2. Issuer Name and Ticker or Trading Symbol GAIN Capital Holdings, Inc. [ GCAP] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) C/O VANTAGEPOINT CAPITAL PARTNERS, 1001 BAYHILL DRIVE, SUITE 300 3. Date of Earliest Transaction (MM/DD/YY) 03/15/2017 (Street) SAN BRUNO, CA94066 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) _____ Form filed by One Reporting Person __ X __ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 03/15/2017 A 12,091 ( 1 ) A $ 0 81,687 ( 2 ) I ( 3 ) Thomas A. Bevilacqua Common Stock 6,576,911 D ( 4 ) ( 8 ) Common Stock 658,417 D ( 5 ) ( 8 ) Common Stock 23,956 D ( 6 ) ( 8 ) Common Stock 1,814,824 D ( 7 ) ( 8 )

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other VANTAGEPOINT VENTURE ASSOCIATES IV LLC C/O VANTAGEPOINT CAPITAL PARTNERS 1001 BAYHILL DRIVE, SUITE 300 SAN BRUNO, CA94066 X VANTAGEPOINT VENTURE PARTNERS IV Q LP C/O VANTAGEPOINT CAPITAL PARTNERS 1001 BAYHILL DRIVE, SUITE 300 SAN BRUNO, CA94066 X VANTAGEPOINT VENTURE PARTNERS IV LP C/O VANTAGEPOINT CAPITAL PARTNERS 1001 BAYHILL DRIVE, SUITE 300 SAN BRUNO, CA94066 X VANTAGEPOINT VENTURE PARTNERS IV PRINCIPALS FUND LP C/O VANTAGEPOINT CAPITAL PARTNERS 1001 BAYHILL DRIVE, SUITE 300 SAN BRUNO, CA94066 X VP NEW YORK VENTURE PARTNERS LP C/O VANTAGEPOINT CAPITAL PARTNERS 1001 BAYHILL DRIVE, SUITE 300 SAN BRUNO, CA94066 X VantagePoint Management, Inc. C/O VANTAGEPOINT CAPITAL PARTNERS 1001 BAYHILL DRIVE, SUITE 300 SAN BRUNO, CA94066 X SALZMAN ALAN E C/O VANTAGEPOINT CAPITAL PARTNERS 1001 BAYHILL DRIVE, SUITE 300 SAN BRUNO, CA94066 X Signatures VantagePoint Venture Associates IV, L.L.C., By: Alan E. Salzman, Managing Member 03/17/2017 Signature of Reporting Person Date VantagePoint Venture Partners IV (Q), L.P., By: VantagePoint Venture Associates IV, L.L.C., By: Alan E. Salzman, Managing Member 03/17/2017 Signature of Reporting Person Date VantagePoint Venture Partners IV, L.P., By: VantagePoint Venture Associates IV, L.L.C., By: Alan E. Salzman, Managing Member 03/17/2017 Signature of Reporting Person Date VantagePoint Venture Partners IV Principals Fund, L.P., By: VantagePoint Venture Associates IV, L.L.C., By: Alan E. Salzman, Managing Member 03/17/2017 Signature of Reporting Person Date VP New York Venture Partners, L.P., By: VantagePoint Venture Associates IV, L.L.C., By: Alan E. Salzman, Managing Member 03/17/2017 Signature of Reporting Person Date VantagePoint Management, Inc., By: Alan E. Salzman, Chief Executive Officer 03/17/2017 Signature of Reporting Person Date Alan E. Salzman 03/17/2017 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Restricted stock units that vest monthly over one year, beginning on the day immediately following the Company's 2017 Annual Meeting of Stockholders. ( 2 )Includes 12,573 restricted stock units, which vest monthly over one year, beginning on the day immediately after the Company's 2016 Annual Meeting of Stockholders. As of the date of this report, 8,382 shares are vested and 4,191 are unvested. ( 3 )VantagePoint Management, Inc. has the voting and investment control over these shares. Only VantagePoint Management, Inc. and Alan E. Salzman, its Chief Executive Officer, are acquiring beneficial ownership of these shares. ( 4 )By: VantagePoint Venture Partners IV (Q), L.P. ( 5 )By: VantagePoint Venture Partners IV, L.P. ( 6 )By: VantagePoint Venture Partners IV Principals Fund, L.P. ( 7 )By: VP New York Venture Partners, L.P. ( 8 )The General Partner is VantagePoint Venture Associates IV, L.L.C. Alan E. Salzman is a managing member of the General Partner and may be deemed to have voting and investment power with respect to the shares or warrants held by these entities. Mr. Salzman disclaims beneficial ownership of these securities except to the extent of his pecuniary interest therein. The Reporting Persons may be deemed to be acting as a group in relation to their respective holdings in the Issuer, but do not affirm the existence of any such group.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

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