<SEC-DOCUMENT>0001140361-17-022338.txt : 20170525
<SEC-HEADER>0001140361-17-022338.hdr.sgml : 20170525
<ACCEPTANCE-DATETIME>20170525162213
ACCESSION NUMBER:		0001140361-17-022338
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20170509
FILED AS OF DATE:		20170525
DATE AS OF CHANGE:		20170525

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Interactive Brokers Group, Inc.
		CENTRAL INDEX KEY:			0001381197
		STANDARD INDUSTRIAL CLASSIFICATION:	SECURITY BROKERS, DEALERS & FLOTATION COMPANIES [6211]
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		ONE PICKWICK PLAZA
		CITY:			GREENWICH
		STATE:			CT
		ZIP:			06830
		BUSINESS PHONE:		203-618-5800

	MAIL ADDRESS:	
		STREET 1:		ONE PICKWICK PLAZA
		CITY:			GREENWICH
		STATE:			CT
		ZIP:			06830

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Nemser Earl H
		CENTRAL INDEX KEY:			0001391400

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-33440
		FILM NUMBER:		17870257

	MAIL ADDRESS:	
		STREET 1:		ONE PICKWICK PLAZA
		CITY:			GREENWICH
		STATE:			CT
		ZIP:			06830
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2017-05-09</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001381197</issuerCik>
        <issuerName>Interactive Brokers Group, Inc.</issuerName>
        <issuerTradingSymbol>IBKR</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001391400</rptOwnerCik>
            <rptOwnerName>Nemser Earl H</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>ONE PICKWICK PLAZA</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>GREENWICH</rptOwnerCity>
            <rptOwnerState>CT</rptOwnerState>
            <rptOwnerZipCode>06830</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Vice Chairman</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A common stock</value>
            </securityTitle>
            <transactionDate>
                <value>2017-05-09</value>
            </transactionDate>
            <deemedExecutionDate>
                <value>2017-05-24</value>
            </deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>4458</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>35.80</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>96585</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class A common stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>50000</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By IBG Holdings LLC</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">The price represents the closing price of the issuer's Class A common stock as of May 9, 2017, the vesting date.</footnote>
        <footnote id="F2">These shares represent the aggregate number of shares of restricted stock from awards granted under the 2007 Stock Incentive Plan since its inception, less vested shares that were withheld for tax purposes, or sold previously.</footnote>
        <footnote id="F3">Represents number of securities owned by IBG Holdings LLC in which the Reporting Person has a pecuniary interest through his membership interest in IBG Holdings LLC. The shares were acquired in a share for share exchange between IBG Holdings LLC and the issuer, in which each share of Class A common stock of the issuer was acquired by IBG Holdings LLC in exchange for one membership interest in IBG LLC.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Clare Zheng as authorized signatory for Earl H. Nemser</signatureName>
        <signatureDate>2017-05-25</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
