<SEC-DOCUMENT>0001085146-19-000858-index.html : 20190214
<SEC-HEADER>0001085146-19-000858.hdr.sgml : 20190214
<ACCEPTANCE-DATETIME>20190214121810
ACCESSION NUMBER:		0001085146-19-000858
CONFORMED SUBMISSION TYPE:	SC 13G
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20190214
DATE AS OF CHANGE:		20190214

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
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-36786
		FILM NUMBER:		19603410

	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:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13G

	BUSINESS ADDRESS:	
		STREET 1:		ONE BEACON STREET
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02108
		BUSINESS PHONE:		2129089500

	MAIL ADDRESS:	
		STREET 1:		909 THIRD AVENUE
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Robeco Investment Management, Inc.
		DATE OF NAME CHANGE:	20070111
</SEC-HEADER>
<DOCUMENT>
<TYPE>SC 13G
<SEQUENCE>1
<FILENAME>wtm_21419.htm
<DESCRIPTION>ROBECO INVESTMENT MANAGEMENT INC.
<TEXT>
Document 1 - file: wtm_21419.htm

</DOCUMENT>
</SEC-DOCUMENT>