<SEC-DOCUMENT>0001567619-21-003571-index.html : 20210212
<SEC-HEADER>0001567619-21-003571.hdr.sgml : 20210212
<ACCEPTANCE-DATETIME>20210212170256
ACCESSION NUMBER:		0001567619-21-003571
CONFORMED SUBMISSION TYPE:	SC 13G/A
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20210212
DATE AS OF CHANGE:		20210212
GROUP MEMBERS:		BARON CAPITAL GROUP, INC.
GROUP MEMBERS:		BARON CAPITAL MANAGEMENT, INC.
GROUP MEMBERS:		RONALD BARON

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			COSTAR GROUP, INC.
		CENTRAL INDEX KEY:			0001057352
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-BUSINESS SERVICES, NEC [7389]
		IRS NUMBER:				522091509
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13G/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-54369
		FILM NUMBER:		21629165

	BUSINESS ADDRESS:	
		STREET 1:		1331 L STREET, NW
		CITY:			WASHINGTON
		STATE:			DC
		ZIP:			20005
		BUSINESS PHONE:		2023466500

	MAIL ADDRESS:	
		STREET 1:		1331 L STREET, NW
		CITY:			WASHINGTON
		STATE:			DC
		ZIP:			20005

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	COSTAR GROUP INC
		DATE OF NAME CHANGE:	19990805

FILED BY:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			BAMCO INC /NY/
		CENTRAL INDEX KEY:			0001017918
		IRS NUMBER:				133390015
		STATE OF INCORPORATION:			NY
		FISCAL YEAR END:			0228

	FILING VALUES:
		FORM TYPE:		SC 13G/A

	BUSINESS ADDRESS:	
		STREET 1:		767 FIFTH AVENUE
		STREET 2:		49TH FL
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10153
		BUSINESS PHONE:		2125832000

	MAIL ADDRESS:	
		STREET 1:		767 FIFTH AVENUE
		STREET 2:		49TH FL
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10153
</SEC-HEADER>
<DOCUMENT>
<TYPE>SC 13G/A
<SEQUENCE>1
<FILENAME>doc1.htm
<DESCRIPTION>NONE
<TEXT>
Document 1 - file: doc1.htm

</DOCUMENT>
</SEC-DOCUMENT>