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    <submissionType>144</submissionType>
    <filerInfo>
      <filer>
        <filerCredentials>
          <cik>0001314400</cik>
          <ccc>XXXXXXXX</ccc>
        </filerCredentials>
      </filer>
      <liveTestFlag>LIVE</liveTestFlag>



    </filerInfo>
  </headerData>
  <formData>
    <issuerInfo>
      <issuerCik>0001278021</issuerCik>
      <issuerName>MARKETAXESS HOLDINGS INC</issuerName>
      <secFileNumber>001-34091</secFileNumber>
      <issuerAddress>
        <com:street1>55 HUDSON YARDS, 15TH FLOOR</com:street1>
        <com:city>NEW YORK</com:city>
        <com:stateOrCountry>NY</com:stateOrCountry>
        <com:zipCode>10001</com:zipCode>
      </issuerAddress>
      <issuerContactPhone>212-831-6000</issuerContactPhone>
      <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>Pintoff Scott</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
      <relationshipsToIssuer>
        <relationshipToIssuer>Officer</relationshipToIssuer>
      </relationshipsToIssuer>
    </issuerInfo>
    <securitiesInformation>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <brokerOrMarketmakerDetails>
        <name>Charles Schwab &amp; Co., Inc.</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>900</noOfUnitsSold>
      <aggregateMarketValue>216008.00</aggregateMarketValue>
      <noOfUnitsOutstanding>37751975</noOfUnitsOutstanding>
      <approxSaleDate>08/13/2024</approxSaleDate>
      <securitiesExchangeName>NASDAQ</securitiesExchangeName>
    </securitiesInformation>
    <securitiesToBeSold>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <acquiredDate>01/31/2021</acquiredDate>
      <natureOfAcquisitionTransaction>Restricted Stock Lapse</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>MARKETAXESS HOLDINGS INC</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>520</amountOfSecuritiesAcquired>
      <paymentDate>01/31/2021</paymentDate>
      <natureOfPayment>Equity Compensation</natureOfPayment>
    </securitiesToBeSold>
    <securitiesToBeSold>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <acquiredDate>01/31/2024</acquiredDate>
      <natureOfAcquisitionTransaction>Restricted Stock Lapse</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>MARKETAXESS HOLDINGS INC</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>380</amountOfSecuritiesAcquired>
      <paymentDate>01/31/2022</paymentDate>
      <natureOfPayment>Equity Compensation</natureOfPayment>
    </securitiesToBeSold>
    <nothingToReportFlagOnSecuritiesSoldInPast3Months>Y</nothingToReportFlagOnSecuritiesSoldInPast3Months>
    <noticeSignature>
      <noticeDate>08/13/2024</noticeDate>
      <planAdoptionDates>
        <planAdoptionDate>12/07/2023</planAdoptionDate>
      </planAdoptionDates>
      <signature>Scott Pintoff</signature>
    </noticeSignature>
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144
0001314400
XXXXXXXX
LIVE
0001278021
MARKETAXESS HOLDINGS INC
001-34091
55 HUDSON YARDS, 15TH FLOOR
NEW YORK
NY
10001
212-831-6000
Pintoff Scott
Officer
Common
Charles Schwab & Co., Inc.
3000 Schwab Way
Westlake
TX
76262
900
216008.00
37751975
08/13/2024
NASDAQ
Common
01/31/2021
Restricted Stock Lapse
MARKETAXESS HOLDINGS INC
N
520
01/31/2021
Equity Compensation
Common
01/31/2024
Restricted Stock Lapse
MARKETAXESS HOLDINGS INC
N
380
01/31/2022
Equity Compensation
Y
08/13/2024
12/07/2023
Scott Pintoff