-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 SCyb7em9pbXODrZp1MVCzpwYiPis6WQE7ccpz1XTwQ0LpAiGx/cU94gbU9fBjLOL
 XfgBinCfFNqP09jzCsktSQ==

<SEC-DOCUMENT>0001209191-10-062316.txt : 20101222
<SEC-HEADER>0001209191-10-062316.hdr.sgml : 20101222
<ACCEPTANCE-DATETIME>20101222192548
ACCESSION NUMBER:		0001209191-10-062316
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20101220
FILED AS OF DATE:		20101222
DATE AS OF CHANGE:		20101222

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Carlough Daryl
		CENTRAL INDEX KEY:			0001506224

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-35008
		FILM NUMBER:		101270209

	MAIL ADDRESS:	
		STREET 1:		BEDMINSTER ONE
		STREET 2:		135 US HIGHWAY 202/206, SUITE 11
		CITY:			BEDMINSTER
		STATE:			NJ
		ZIP:			07921

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			GAIN Capital Holdings, Inc.
		CENTRAL INDEX KEY:			0001444363
		STANDARD INDUSTRIAL CLASSIFICATION:	 [6221]
		IRS NUMBER:				204568600
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		550 HILLS DRIVE
		CITY:			BEDMINSTER
		STATE:			NJ
		ZIP:			07921
		BUSINESS PHONE:		908-731-0700

	MAIL ADDRESS:	
		STREET 1:		550 HILLS DRIVE
		CITY:			BEDMINSTER
		STATE:			NJ
		ZIP:			07921
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>c10104_4x0.xml
<DESCRIPTION>MAIN DOCUMENT DESCRIPTION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-12-20</periodOfReport>

    <issuer>
        <issuerCik>0001444363</issuerCik>
        <issuerName>GAIN Capital Holdings, Inc.</issuerName>
        <issuerTradingSymbol>GCAP</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001506224</rptOwnerCik>
            <rptOwnerName>Carlough Daryl</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C.O. GAIN CAPITAL HOLDINGS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>BEDMINSTER NEW JERSEY</rptOwnerCity>
            <rptOwnerState>NJ</rptOwnerState>
            <rptOwnerZipCode>07921</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief Accounting Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-12-20</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>9.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <ownerSignature>
        <signatureName>/s/ Daryl Carlough</signatureName>
        <signatureDate>2010-12-21</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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