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            <ccc>XXXXXXXX</ccc>
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        <liveTestFlag>LIVE</liveTestFlag>
  
  
  
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        <secFileNumber>000-51829</secFileNumber>
        <issuerAddress>
          <com:street1>2450 N.  Street  N.W.</com:street1>
          <com:city>Washington</com:city>
          <com:stateOrCountry>DC</com:stateOrCountry>
          <com:zipCode>20037</com:zipCode>
        </issuerAddress>
        <issuerContactPhone>202-295-4200</issuerContactPhone>
        <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>David Schaeffer</nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>
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          <address>
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            <com:street2>6th Floor</com:street2>
            <com:city>New York</com:city>
            <com:stateOrCountry>NY</com:stateOrCountry>
            <com:zipCode>10017</com:zipCode>
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        </brokerOrMarketmakerDetails>
        <noOfUnitsSold>20000</noOfUnitsSold>
        <aggregateMarketValue>1393000</aggregateMarketValue>
        <noOfUnitsOutstanding>48623846</noOfUnitsOutstanding>
        <approxSaleDate>12/13/2023</approxSaleDate>
        <securitiesExchangeName>NASDAQ</securitiesExchangeName>
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        <securitiesClassTitle>Common Stock</securitiesClassTitle>
        <acquiredDate>02/01/2013</acquiredDate>
        <natureOfAcquisitionTransaction>Stock Grant</natureOfAcquisitionTransaction>
        <nameOfPersonfromWhomAcquired>Issuer</nameOfPersonfromWhomAcquired>
        <isGiftTransaction>N</isGiftTransaction>
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        <paymentDate>02/01/2013</paymentDate>
        <natureOfPayment>Cash</natureOfPayment>
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      <securitiesToBeSold>
        <securitiesClassTitle>Common Stock</securitiesClassTitle>
        <acquiredDate>03/01/2013</acquiredDate>
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        <paymentDate>03/01/2013</paymentDate>
        <natureOfPayment>Cash</natureOfPayment>
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          <name>David Schaeffer</name>
          <address>
            <com:street1>C/o Cogent Communications Holdings Inc</com:street1>
            <com:street2>2450 N. Street N.W.</com:street2>
            <com:city>Washington</com:city>
            <com:stateOrCountry>DC</com:stateOrCountry>
            <com:zipCode>20037</com:zipCode>
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        </sellerDetails>
        <securitiesClassTitle>Common Stock</securitiesClassTitle>
        <saleDate>09/15/2023</saleDate>
        <amountOfSecuritiesSold>18191</amountOfSecuritiesSold>
        <grossProceeds>1197364</grossProceeds>
      </securitiesSoldInPast3Months>
      <securitiesSoldInPast3Months>
        <sellerDetails>
          <name>David Schaeffer</name>
          <address>
            <com:street1>C/o Cogent Communications Holdings Inc</com:street1>
            <com:street2>2450 N. Street N.W.</com:street2>
            <com:city>Washington</com:city>
            <com:stateOrCountry>DC</com:stateOrCountry>
            <com:zipCode>20037</com:zipCode>
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        </sellerDetails>
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        <saleDate>11/14/2023</saleDate>
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        <grossProceeds>2654800</grossProceeds>
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      <securitiesSoldInPast3Months>
        <sellerDetails>
          <name>David Schaeffer</name>
          <address>
            <com:street1>C/o Cogent Communications Holdings Inc</com:street1>
            <com:street2>2450 N. Street N.W.</com:street2>
            <com:city>Washington</com:city>
            <com:stateOrCountry>DC</com:stateOrCountry>
            <com:zipCode>20037</com:zipCode>
          </address>
        </sellerDetails>
        <securitiesClassTitle>Common Stock</securitiesClassTitle>
        <saleDate>11/30/2023</saleDate>
        <amountOfSecuritiesSold>3396</amountOfSecuritiesSold>
        <grossProceeds>218409</grossProceeds>
      </securitiesSoldInPast3Months>
      <securitiesSoldInPast3Months>
        <sellerDetails>
          <name>David Schaeffer</name>
          <address>
            <com:street1>C/o Cogent Communications Holdings Inc</com:street1>
            <com:street2>2450 N. Street N.W.</com:street2>
            <com:city>Washington</com:city>
            <com:stateOrCountry>DC</com:stateOrCountry>
            <com:zipCode>20037</com:zipCode>
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        <saleDate>12/01/2023</saleDate>
        <amountOfSecuritiesSold>36604</amountOfSecuritiesSold>
        <grossProceeds>2385691</grossProceeds>
      </securitiesSoldInPast3Months>
      <noticeSignature>
        <noticeDate>12/13/2023</noticeDate>
        <signature>/s/ J.P. Morgan Securities LLC as agent and attorney-in-fact for David Schaeffer</signature>
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text: 144
  0001166976
  XXXXXXXX
  LIVE
  0001158324
  Cogent Communications Holdings, Inc.
  000-51829
  2450 N.  Street  N.W.
  Washington
  DC
  20037
  202-295-4200
  David Schaeffer
  Chairman / CEO / President
  Common Stock
  J.P. Morgan Securities LLC
  390 Madison Avenue
  6th Floor
  New York
  NY
  10017
  20000
  1393000
  48623846
  12/13/2023
  NASDAQ
  Common Stock
  02/01/2013
  Stock Grant
  Issuer
  N
  10000
  02/01/2013
  Cash
  Common Stock
  03/01/2013
  Stock Grant
  Issuer
  N
  10000
  03/01/2013
  Cash
  N
  David Schaeffer
  C/o Cogent Communications Holdings Inc
  2450 N. Street N.W.
  Washington
  DC
  20037
  Common Stock
  09/15/2023
  18191
  1197364
  David Schaeffer
  C/o Cogent Communications Holdings Inc
  2450 N. Street N.W.
  Washington
  DC
  20037
  Common Stock
  11/14/2023
  40000
  2654800
  David Schaeffer
  C/o Cogent Communications Holdings Inc
  2450 N. Street N.W.
  Washington
  DC
  20037
  Common Stock
  11/30/2023
  3396
  218409
  David Schaeffer
  C/o Cogent Communications Holdings Inc
  2450 N. Street N.W.
  Washington
  DC
  20037
  Common Stock
  12/01/2023
  36604
  2385691
  12/13/2023
  /s/ J.P. Morgan Securities LLC as agent and attorney-in-fact for David Schaeffer