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      <liveTestFlag>LIVE</liveTestFlag>



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    <issuerInfo>
      <issuerCik>0001156375</issuerCik>
      <issuerName>CME GROUP INC.</issuerName>
      <secFileNumber>001-31553</secFileNumber>
      <issuerAddress>
        <com:street1>20 S. WACKER DR.</com:street1>
        <com:city>CHICAGO</com:city>
        <com:stateOrCountry>IL</com:stateOrCountry>
        <com:zipCode>60606</com:zipCode>
      </issuerAddress>
      <issuerContactPhone>3129301000</issuerContactPhone>
      <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>Cook Elizabeth A</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
      <relationshipsToIssuer>
        <relationshipToIssuer>Director</relationshipToIssuer>
      </relationshipsToIssuer>
    </issuerInfo>
    <securitiesInformation>
      <securitiesClassTitle>Common Class A</securitiesClassTitle>
      <brokerOrMarketmakerDetails>
        <name>Charles Schwab Corporation</name>
        <address>
          <com:street1>3000 Schwab Way</com:street1>
          <com:city>Westlake</com:city>
          <com:stateOrCountry>TX</com:stateOrCountry>
          <com:zipCode>76262</com:zipCode>
        </address>
      </brokerOrMarketmakerDetails>
      <noOfUnitsSold>750</noOfUnitsSold>
      <aggregateMarketValue>169860.00</aggregateMarketValue>
      <noOfUnitsOutstanding>360359063</noOfUnitsOutstanding>
      <approxSaleDate>11/12/2024</approxSaleDate>
      <securitiesExchangeName>NASDAQ</securitiesExchangeName>
    </securitiesInformation>
    <securitiesToBeSold>
      <securitiesClassTitle>Common Class A</securitiesClassTitle>
      <acquiredDate>06/25/2018</acquiredDate>
      <natureOfAcquisitionTransaction>Employee Compensation</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>601</amountOfSecuritiesAcquired>
      <paymentDate>06/18/2018</paymentDate>
      <natureOfPayment>Employee Compensation</natureOfPayment>
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    <securitiesToBeSold>
      <securitiesClassTitle>Common Class A</securitiesClassTitle>
      <acquiredDate>06/25/2020</acquiredDate>
      <natureOfAcquisitionTransaction>Employee Compensation</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>3</amountOfSecuritiesAcquired>
      <paymentDate>06/25/2020</paymentDate>
      <natureOfPayment>Employee Compensation</natureOfPayment>
    </securitiesToBeSold>
    <securitiesToBeSold>
      <securitiesClassTitle>Common Class A</securitiesClassTitle>
      <acquiredDate>04/19/2021</acquiredDate>
      <natureOfAcquisitionTransaction>Employee Compensation</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>9684</amountOfSecuritiesAcquired>
      <paymentDate>04/19/2021</paymentDate>
      <natureOfPayment>Employee Compensation</natureOfPayment>
    </securitiesToBeSold>
    <nothingToReportFlagOnSecuritiesSoldInPast3Months>Y</nothingToReportFlagOnSecuritiesSoldInPast3Months>
    <remarks>Shares to be sold in ELIZABETH ANNE COOK TRUST</remarks>
    <noticeSignature>
      <noticeDate>11/12/2024</noticeDate>
      <signature>Elizabeth Cook</signature>
    </noticeSignature>
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144
0001643475
XXXXXXXX
LIVE
0001156375
CME GROUP INC.
001-31553
20 S. WACKER DR.
CHICAGO
IL
60606
3129301000
Cook Elizabeth A
Director
Common Class A
Charles Schwab Corporation
3000 Schwab Way
Westlake
TX
76262
750
169860.00
360359063
11/12/2024
NASDAQ
Common Class A
06/25/2018
Employee Compensation
Issuer
N
601
06/18/2018
Employee Compensation
Common Class A
06/25/2020
Employee Compensation
Issuer
N
3
06/25/2020
Employee Compensation
Common Class A
04/19/2021
Employee Compensation
Issuer
N
9684
04/19/2021
Employee Compensation
Y
Shares to be sold in ELIZABETH ANNE COOK TRUST
11/12/2024
Elizabeth Cook