<SEC-DOCUMENT>0001567619-19-003854-index.html : 20190214
<SEC-HEADER>0001567619-19-003854.hdr.sgml : 20190214
<ACCEPTANCE-DATETIME>20190213180502
ACCESSION NUMBER:		0001567619-19-003854
CONFORMED SUBMISSION TYPE:	SC 13G/A
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20190214
DATE AS OF CHANGE:		20190213
GROUP MEMBERS:		BARON CAPITAL GROUP, INC.
GROUP MEMBERS:		BARON CAPITAL MANAGEMENT, INC.
GROUP MEMBERS:		RONALD BARON

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Altair Engineering Inc.
		CENTRAL INDEX KEY:			0001701732
		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-PREPACKAGED SOFTWARE [7372]
		IRS NUMBER:				382591828
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13G/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-90370
		FILM NUMBER:		19599211

	BUSINESS ADDRESS:	
		STREET 1:		1820 E. BIG BEAVER ROAD
		CITY:			TROY
		STATE:			MI
		ZIP:			48083
		BUSINESS PHONE:		248-614-2400

	MAIL ADDRESS:	
		STREET 1:		1820 E. BIG BEAVER ROAD
		CITY:			TROY
		STATE:			MI
		ZIP:			48083

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Altair Engineering Ing.
		DATE OF NAME CHANGE:	20170322

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>