<SEC-DOCUMENT>0001085146-20-000566-index.html : 20200211
<SEC-HEADER>0001085146-20-000566.hdr.sgml : 20200211
<ACCEPTANCE-DATETIME>20200211124159
ACCESSION NUMBER:		0001085146-20-000566
CONFORMED SUBMISSION TYPE:	SC 13G/A
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20200211
DATE AS OF CHANGE:		20200211

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			WHITE MOUNTAINS INSURANCE GROUP LTD
		CENTRAL INDEX KEY:			0000776867
		STANDARD INDUSTRIAL CLASSIFICATION:	FIRE, MARINE & CASUALTY INSURANCE [6331]
		IRS NUMBER:				942708455
		STATE OF INCORPORATION:			D0
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13G/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-36786
		FILM NUMBER:		20595504

	BUSINESS ADDRESS:	
		STREET 1:		80 SOUTH MAIN ST
		CITY:			HANOVER
		STATE:			NH
		ZIP:			03755
		BUSINESS PHONE:		603 640 2200

	MAIL ADDRESS:	
		STREET 1:		80 SOUTH MAIN STREET
		CITY:			HANOVER
		STATE:			NH
		ZIP:			03755

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	WHITE MOUNTAINS INSURANCE GROUP INC
		DATE OF NAME CHANGE:	19990603

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	FUND AMERICAN ENTERPRISES HOLDINGS INC
		DATE OF NAME CHANGE:	19920703

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	FUND AMERICAN COMPANIES INC
		DATE OF NAME CHANGE:	19920701

FILED BY:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Boston Partners
		CENTRAL INDEX KEY:			0001386060
		IRS NUMBER:				980202744
		STATE OF INCORPORATION:			NY
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13G/A

	BUSINESS ADDRESS:	
		STREET 1:		ONE BEACON STREET
		STREET 2:		30TH FLOOR
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02108
		BUSINESS PHONE:		2129089500

	MAIL ADDRESS:	
		STREET 1:		ONE BEACON STREET
		STREET 2:		30TH FLOOR
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02108

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Robeco Investment Management, Inc.
		DATE OF NAME CHANGE:	20070111
</SEC-HEADER>
<DOCUMENT>
<TYPE>SC 13G/A
<SEQUENCE>1
<FILENAME>wtma1_21120.htm
<DESCRIPTION>ROBECO INVESTMENT MANAGEMENT INC.
<TEXT>
Document 1 - file: wtma1_21120.htm

</DOCUMENT>
</SEC-DOCUMENT>