Sec Form 3 Filing - O'Grady Crevan @ GAIN Capital Holdings, Inc. - 2010-12-14

FORM 3 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 O'Grady Crevan 2. Issuer Name and Ticker or Trading Symbol GAIN Capital Holdings, Inc. [ GCAP] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director _____ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) SEAGRAM BUILDING, 375 PARK AVENUE SUITE 3001 3. Date of Earliest Transaction (MM/DD/YY) 12/14/2010 (Street) NEW YORK, NY10152 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ 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

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 O'Grady Crevan SEAGRAM BUILDING 375 PARK AVENUE SUITE 3001 NEW YORK, NY10152 X Signatures /s/ Crevan O'Grady 12/14/2010 Signature of Reporting Person Date

Explanation of Responses:

Remarks: Mr. O'Grady is employed by a subsidiary of 3i Group plc, a public limited company whose ordinary shares are listed on the London StockExchange ("3i Group"). Mr. O'Grady has de minimis equity ownership of 3i Group resulting from his participation in 3i Group'semployee share schemes. Mr O'Grady also participates in carried interest and bonus schemes that are based in part on the performanceof investments made by funds managed by affiliates of 3i Group, including the 3i Funds (defined below). 3i Group is the indirectbeneficial owner of all general partnership and limited partnership interests in 3i U.S. Growth Capital (USA) D LP ("GrowthCapital D") and 3i U.S. Growth Capital (USA) P LP ("Growth Capital P"). 3i Group is an indirect limited partner in3i U.S. Growth Capital (USA) E LP ("Growth Capital E"), 3i U.S. Growth Partners LP ("Growth Partners") and 3iU.S. Technology Partners III LP ("Technology Partners" and, together with Growth Capital D, Growth Capital E, Growth CapitalP and Growth Partners, the "3i Funds"). The 3i Funds beneficially own shares of the issuer's Series E Preferred Stock(the "Preferred Stock"). Growth Partners and Technology Partners beneficially own a right to receive deferred cash considerationwith respect to shares of the Preferred Stock (together with the Preferred Stock, the "Securities"). Investment authorityover the shares of Preferred Stock held by the 3i Funds is held by indirect subsidiaries of 3i Group that are general partnersof the 3i Funds. Mr. O'Grady disclaims beneficial ownership of all Securities.

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).

** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).

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