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    <filerInfo>
      <filer>
        <filerCredentials>
          <cik>0001718249</cik>
          <ccc>XXXXXXXX</ccc>
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      </filer>
      <liveTestFlag>LIVE</liveTestFlag>



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    <issuerInfo>
      <issuerCik>0000947484</issuerCik>
      <issuerName>ARCH CAPITAL GROUP LTD.</issuerName>
      <secFileNumber>001-16209</secFileNumber>
      <issuerAddress>
        <com:street1>WATERLOO HOUSE, GROUND FLOOR</com:street1>
        <com:street2>100 PITTS BAY ROAD</com:street2>
        <com:city>PEMBROKE</com:city>
        <com:stateOrCountry>D0</com:stateOrCountry>
        <com:zipCode>HM 08</com:zipCode>
      </issuerAddress>
      <issuerContactPhone>441-278-9250</issuerContactPhone>
      <nameOfPersonForWhoseAccountTheSecuritiesAreToBeSold>Rajeh Maamoun</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>40000</noOfUnitsSold>
      <aggregateMarketValue>3056199.00</aggregateMarketValue>
      <noOfUnitsOutstanding>372422622</noOfUnitsOutstanding>
      <approxSaleDate>05/09/2023</approxSaleDate>
      <securitiesExchangeName>NASDAQ</securitiesExchangeName>
    </securitiesInformation>
    <securitiesToBeSold>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <acquiredDate>05/05/2021</acquiredDate>
      <natureOfAcquisitionTransaction>Stock Appreciation Right</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>ARCH CAPITAL GROUP LTD.</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>20484</amountOfSecuritiesAcquired>
      <paymentDate>05/05/2021</paymentDate>
      <natureOfPayment>Equity Compensation</natureOfPayment>
    </securitiesToBeSold>
    <securitiesToBeSold>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <acquiredDate>02/25/2023</acquiredDate>
      <natureOfAcquisitionTransaction>Restricted Stock Lapse</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>ARCH CAPITAL GROUP LTD.</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>2037</amountOfSecuritiesAcquired>
      <paymentDate>02/25/2023</paymentDate>
      <natureOfPayment>Equity Compensation</natureOfPayment>
    </securitiesToBeSold>
    <securitiesToBeSold>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <acquiredDate>02/26/2023</acquiredDate>
      <natureOfAcquisitionTransaction>Restricted Stock Lapse</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>ARCH CAPITAL GROUP LTD.</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>2696</amountOfSecuritiesAcquired>
      <paymentDate>02/26/2023</paymentDate>
      <natureOfPayment>Equity Compensation</natureOfPayment>
    </securitiesToBeSold>
    <securitiesToBeSold>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <acquiredDate>02/27/2023</acquiredDate>
      <natureOfAcquisitionTransaction>Restricted Stock Lapse</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>ARCH CAPITAL GROUP LTD.</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>2041</amountOfSecuritiesAcquired>
      <paymentDate>02/27/2023</paymentDate>
      <natureOfPayment>Equity Compensation</natureOfPayment>
    </securitiesToBeSold>
    <securitiesToBeSold>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <acquiredDate>03/10/2023</acquiredDate>
      <natureOfAcquisitionTransaction>Performance Stock Lapse</natureOfAcquisitionTransaction>
      <nameOfPersonfromWhomAcquired>ARCH CAPITAL GROUP LTD.</nameOfPersonfromWhomAcquired>
      <isGiftTransaction>N</isGiftTransaction>
      <amountOfSecuritiesAcquired>12742</amountOfSecuritiesAcquired>
      <paymentDate>03/10/2023</paymentDate>
      <natureOfPayment>Equity Compensation</natureOfPayment>
    </securitiesToBeSold>
    <nothingToReportFlagOnSecuritiesSoldInPast3Months>N</nothingToReportFlagOnSecuritiesSoldInPast3Months>
    <securitiesSoldInPast3Months>
      <sellerDetails>
        <name>Rajeh Maamoun</name>
        <address>
          <com:street1>WATERLOO HOUSE, GROUND FLOOR</com:street1>
          <com:street2>100 PITTS BAY ROAD</com:street2>
          <com:city>PEMBROKE</com:city>
          <com:stateOrCountry>D0</com:stateOrCountry>
          <com:zipCode>HM 08</com:zipCode>
        </address>
      </sellerDetails>
      <securitiesClassTitle>Common</securitiesClassTitle>
      <saleDate>05/01/2023</saleDate>
      <amountOfSecuritiesSold>35940</amountOfSecuritiesSold>
      <grossProceeds>2733882.00</grossProceeds>
    </securitiesSoldInPast3Months>
    <noticeSignature>
      <noticeDate>05/09/2023</noticeDate>
      <signature>MAAMOUN RAJEH</signature>
    </noticeSignature>
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144
0001718249
XXXXXXXX
LIVE
0000947484
ARCH CAPITAL GROUP LTD.
001-16209
WATERLOO HOUSE, GROUND FLOOR
100 PITTS BAY ROAD
PEMBROKE
D0
HM 08
441-278-9250
Rajeh Maamoun
Officer
Common
Charles Schwab & Co., Inc.
3000 Schwab Way
Westlake
TX
76262
40000
3056199.00
372422622
05/09/2023
NASDAQ
Common
05/05/2021
Stock Appreciation Right
ARCH CAPITAL GROUP LTD.
N
20484
05/05/2021
Equity Compensation
Common
02/25/2023
Restricted Stock Lapse
ARCH CAPITAL GROUP LTD.
N
2037
02/25/2023
Equity Compensation
Common
02/26/2023
Restricted Stock Lapse
ARCH CAPITAL GROUP LTD.
N
2696
02/26/2023
Equity Compensation
Common
02/27/2023
Restricted Stock Lapse
ARCH CAPITAL GROUP LTD.
N
2041
02/27/2023
Equity Compensation
Common
03/10/2023
Performance Stock Lapse
ARCH CAPITAL GROUP LTD.
N
12742
03/10/2023
Equity Compensation
N
Rajeh Maamoun
WATERLOO HOUSE, GROUND FLOOR
100 PITTS BAY ROAD
PEMBROKE
D0
HM 08
Common
05/01/2023
35940
2733882.00
05/09/2023
MAAMOUN RAJEH