<SEC-DOCUMENT>0001897612-25-000527.txt : 20251114
<SEC-HEADER>0001897612-25-000527.hdr.sgml : 20251114
<ACCEPTANCE-DATETIME>20251114121824
ACCESSION NUMBER:		0001897612-25-000527
CONFORMED SUBMISSION TYPE:	SCHEDULE 13G/A
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20251114
DATE AS OF CHANGE:		20251114

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MARKETAXESS HOLDINGS INC
		CENTRAL INDEX KEY:			0001278021
		STANDARD INDUSTRIAL CLASSIFICATION:	SECURITY BROKERS, DEALERS & FLOTATION COMPANIES [6211]
		ORGANIZATION NAME:           	09 Crypto Assets
		EIN:				522230784
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SCHEDULE 13G/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-80409
		FILM NUMBER:		251483380

	BUSINESS ADDRESS:	
		STREET 1:		55 HUDSON YARDS, 15TH FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10001
		BUSINESS PHONE:		212-831-6000

	MAIL ADDRESS:	
		STREET 1:		55 HUDSON YARDS, 15TH FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10001

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	MARKETAXESS HOLDING INC
		DATE OF NAME CHANGE:	20040129

FILED BY:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			T. Rowe Price Investment Management, Inc.
		CENTRAL INDEX KEY:			0001897612
		ORGANIZATION NAME:           	
		EIN:				854328500
		STATE OF INCORPORATION:			MD
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SCHEDULE 13G/A

	BUSINESS ADDRESS:	
		STREET 1:		1307 POINT STREET
		CITY:			BALTIMORE
		STATE:			MD
		ZIP:			21231
		BUSINESS PHONE:		000-000-0000

	MAIL ADDRESS:	
		STREET 1:		1307 POINT STREET
		CITY:			BALTIMORE
		STATE:			MD
		ZIP:			21231
</SEC-HEADER>
<DOCUMENT>
<TYPE>SCHEDULE 13G/A
<SEQUENCE>1
<FILENAME>primary_doc.xml
<TEXT>
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    <headerData>
        <submissionType>SCHEDULE 13G/A</submissionType>
        <previousAccessionNumber>0001897612-24-001925</previousAccessionNumber>
        <filerInfo>
            <filer>
                <filerCredentials>
                    <cik>0001897612</cik>
                    <ccc>XXXXXXXX</ccc>
                </filerCredentials>
            </filer>
            <liveTestFlag>LIVE</liveTestFlag>


        </filerInfo>
    </headerData>
    <formData>
        <coverPageHeader>
            <amendmentNo>1</amendmentNo>
            <securitiesClassTitle>COMMON STOCK</securitiesClassTitle>
            <eventDateRequiresFilingThisStatement>09/30/2025</eventDateRequiresFilingThisStatement>
            <issuerInfo>
                <issuerCik>0001278021</issuerCik>
                <issuerName>MARKETAXESS HOLDINGS INC</issuerName>
                <issuerCusip>57060D108</issuerCusip>
                <issuerPrincipalExecutiveOfficeAddress>
                    <ns2:street1>55 HUDSON YARDS, 15TH FLOOR</ns2:street1>
                    <ns2:city>NEW YORK</ns2:city>
                    <ns2:stateOrCountry>NY</ns2:stateOrCountry>
                    <ns2:zipCode>10001</ns2:zipCode>
                </issuerPrincipalExecutiveOfficeAddress>
            </issuerInfo>
            <designateRulesPursuantThisScheduleFiled>
                <designateRulePursuantThisScheduleFiled>Rule 13d-1(b)</designateRulePursuantThisScheduleFiled>
            </designateRulesPursuantThisScheduleFiled>
        </coverPageHeader>
        <coverPageHeaderReportingPersonDetails>

            <reportingPersonName>T. Rowe Price Investment Management, Inc.</reportingPersonName>
            <citizenshipOrOrganization>MD</citizenshipOrOrganization>
            <reportingPersonBeneficiallyOwnedNumberOfShares>
                <soleVotingPower>1367413</soleVotingPower>
                <sharedVotingPower>0</sharedVotingPower>
                <soleDispositivePower>1370694</soleDispositivePower>
                <sharedDispositivePower>0</sharedDispositivePower>
            </reportingPersonBeneficiallyOwnedNumberOfShares>
            <reportingPersonBeneficiallyOwnedAggregateNumberOfShares>1370694</reportingPersonBeneficiallyOwnedAggregateNumberOfShares>
            <aggregateAmountExcludesCertainSharesFlag>N</aggregateAmountExcludesCertainSharesFlag>
            <classPercent>3.7</classPercent>
            <typeOfReportingPerson>IA</typeOfReportingPerson>
        </coverPageHeaderReportingPersonDetails>
        <items>
            <item1>
                <issuerName>MARKETAXESS HOLDINGS INC</issuerName>
                <issuerPrincipalExecutiveOfficeAddress>55 HUDSON YARDS, 15TH FLOOR, NEW YORK, NY, 10001</issuerPrincipalExecutiveOfficeAddress>
            </item1>
            <item2>
                <filingPersonName>T. Rowe Price Investment Management, Inc.</filingPersonName>
                <principalBusinessOfficeOrResidenceAddress>1307 Point Street, Baltimore, MD 21231</principalBusinessOfficeOrResidenceAddress>
                <citizenship>Maryland</citizenship>
            </item2>
            <item3>
                <notApplicableFlag>N</notApplicableFlag>
                <typeOfPersonFiling>IA</typeOfPersonFiling>
            </item3>
            <item4>
                <amountBeneficiallyOwned>1370694</amountBeneficiallyOwned>
                <classPercent>3.7</classPercent>
                <numberOfSharesPersonHas>
                    <solePowerOrDirectToVote>1367413</solePowerOrDirectToVote>
                    <sharedPowerOrDirectToVote>0</sharedPowerOrDirectToVote>
                    <solePowerOrDirectToDispose>1370694</solePowerOrDirectToDispose>
                    <sharedPowerOrDirectToDispose>0</sharedPowerOrDirectToDispose>
                </numberOfSharesPersonHas>
            </item4>
            <item5>
                <notApplicableFlag>N</notApplicableFlag>
                <classOwnership5PercentOrLess>Y</classOwnership5PercentOrLess>
            </item5>
            <item6>
                <notApplicableFlag>Y</notApplicableFlag>
            </item6>
            <item7>
                <notApplicableFlag>Y</notApplicableFlag>
            </item7>
            <item8>
                <notApplicableFlag>Y</notApplicableFlag>
            </item8>
            <item9>
                <notApplicableFlag>Y</notApplicableFlag>
            </item9>
            <item10>
                <notApplicableFlag>N</notApplicableFlag>
                <certifications>By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11. T. Rowe Price Investment Management, Inc. hereby declares and affirms that the filing of Schedule 13G shall not be construed as an admission that Price Investment Management is the beneficial owner of the securities referred to, which beneficial ownership is expressly denied.</certifications>
            </item10>
        </items>
        <signatureInformation>
            <reportingPersonName>T. Rowe Price Investment Management, Inc.</reportingPersonName>
            <signatureDetails>
                <signature>Ellen York</signature>
                <title>Vice President</title>
                <date>11/14/2025</date>
            </signatureDetails>
        </signatureInformation>
    </formData>
</edgarSubmission>
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</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
