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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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<SEC-DOCUMENT>0001156375-09-000160.txt : 20091014
<SEC-HEADER>0001156375-09-000160.hdr.sgml : 20091014
<ACCEPTANCE-DATETIME>20091014164040
ACCESSION NUMBER:		0001156375-09-000160
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20090921
FILED AS OF DATE:		20091014
DATE AS OF CHANGE:		20091014

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Niciforo Joseph
		CENTRAL INDEX KEY:			0001361846

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-31553
		FILM NUMBER:		091119505

	MAIL ADDRESS:	
		STREET 1:		20 S. WACKER DRIVE
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60606

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CME GROUP INC.
		CENTRAL INDEX KEY:			0001156375
		STANDARD INDUSTRIAL CLASSIFICATION:	SECURITY & COMMODITY BROKERS, DEALERS, EXCHANGES & SERVICES [6200]
		IRS NUMBER:				364459170
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		20 S. WACKER DR.
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60606
		BUSINESS PHONE:		3129303011

	MAIL ADDRESS:	
		STREET 1:		20 S. WACKER DR.
		CITY:			CHICAGO
		STATE:			IL
		ZIP:			60606

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	CHICAGO MERCANTILE EXCHANGE HOLDINGS INC
		DATE OF NAME CHANGE:	20010802
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgardoc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2009-09-21</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001156375</issuerCik>
        <issuerName>CME GROUP INC.</issuerName>
        <issuerTradingSymbol>CME</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001361846</rptOwnerCik>
            <rptOwnerName>Niciforo Joseph</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>20 S. WACKER DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>CHICAGO</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60606</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock Class B1</value>
            </securityTitle>
            <transactionDate>
                <value>2009-10-12</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>297.79</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>by Partnership</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock Class B3</value>
            </securityTitle>
            <transactionDate>
                <value>2009-09-21</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>304.6</value>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>by Partnership</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Represents the closing price for our Class A common stock on October 12, 2009. On October 12, 2009, Henning and Carey Proprietary Trading L.L.C. of which Mr. Niciforo is a general partner purchased a CME membership along with the associated share of Class B-1 common stock. The Class B common stock of CME Group Inc. is not listed on a national securities exchange or traded in an organized over-the-counter market. Each class of the Class B common stock is associated with a membership in a specific division of the exchange. We assume that because the Class B shares have the same equitable interest in our earnings and the same dividend payments as our Class A shares, that if reported separately from the associated trading rights, they would have the same market price as our Class A common stock.</footnote>
        <footnote id="F2">Represents the closing price for our Class A common stock on September 21, 2009. On September 21, 2009, Henning and Carey Proprietary Trading L.L.C. of which Mr. Niciforo is a general partner purchased an Index and Option Market (IOM) membership along with the associated share of Class B-3 common stock. The Class B common stock of CME Group Inc. is not listed on a national securities exchange or traded in an organized over-the-counter market. Each class of the Class B common stock is associated with a membership in a specific division of the exchange. We assume that because the Class B shares have the same equitable interest in our earnings and the same dividend payments as our Class A shares, that if reported separately from the associated trading rights, they would have the same market price as our Class A common stock.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>By: Margaret C. Austin  For: Joseph Niciforo</signatureName>
        <signatureDate>2009-10-14</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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