<SEC-DOCUMENT>0000080255-20-001156-index.html : 20200214
<SEC-HEADER>0000080255-20-001156.hdr.sgml : 20200214
<ACCEPTANCE-DATETIME>20200214133013
ACCESSION NUMBER:		0000080255-20-001156
CONFORMED SUBMISSION TYPE:	SC 13G/A
CONFIRMING COPY:	
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20200214
DATE AS OF CHANGE:		20200214

SUBJECT COMPANY:	

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

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

	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:			PRICE T ROWE ASSOCIATES INC /MD/
		CENTRAL INDEX KEY:			0000080255
		STANDARD INDUSTRIAL CLASSIFICATION:	SECURITY & COMMODITY BROKERS, DEALERS, EXCHANGES & SERVICES [6200]
		IRS NUMBER:				520556948
		STATE OF INCORPORATION:			MD
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13G/A

	BUSINESS ADDRESS:	
		STREET 1:		100 EAST PRATT ST
		CITY:			BALTIMORE
		STATE:			MD
		ZIP:			21202
		BUSINESS PHONE:		(410)345-6603

	MAIL ADDRESS:	
		STREET 1:		P.O. BOX 89000
		CITY:			BALTIMORE
		STATE:			MD
		ZIP:			21289
</SEC-HEADER>
<DOCUMENT>
<TYPE>SC 13G/A
<SEQUENCE>1
<FILENAME>mktx13gadec19.txt
<TEXT>
Document 1 - file: mktx13gadec19.txt

</DOCUMENT>
</SEC-DOCUMENT>