Who Owns WHITE MTNS INS GROUP LTD (WTM)? -- Institutional Holders (2026-06-30)

394 institutions reported holding $4.61B of WHITE MTNS INS GROUP LTD (WTM) in SEC 13F filings for 2026-06-30. Largest institutional holders: VANGUARD GROUP INC ($495.0M), DIMENSIONAL FUND ADVISORS LP ($329.6M), NEUBERGER BERMAN GROUP LLC ($247.0M), BlackRock, Inc. ($244.4M), River Road Asset Management, LLC ($240.3M). Source: SEC Form 13F.

RankInstitutionValueSharesChange
1VANGUARD GROUP INC$495.0M238,721Trimmed
2DIMENSIONAL FUND ADVISORS LP$329.6M158,954Added
3NEUBERGER BERMAN GROUP LLC$247.0M119,141Trimmed
4BlackRock, Inc.$244.4M117,871Added
5River Road Asset Management, LLC$240.3M115,880Trimmed
6FULLER & THALER ASSET MANAGEMENT, INC.$211.3M101,892Trimmed
7COOKE & BIELER LP$176.5M85,120Trimmed
8Wallace Capital Management Inc.$166.0M80,067Added
9FIDUCIARY MANAGEMENT INC /WI/$138.0M66,550Trimmed
10GENDELL JEFFREY L$122.8M59,243Added
11Boston Partners$115.3M55,569Trimmed
12LONDON CO OF VIRGINIA$112.1M54,025Trimmed
13STATE STREET CORP$104.2M50,257Added
14GEODE CAPITAL MANAGEMENT, LLC$102.5M49,412Added
15MORGAN STANLEY$97.2M46,866Trimmed
16REINHART PARTNERS, LLC.$92.3M44,480Added
17T. Rowe Price Investment Management, Inc.$71.0M34,237Trimmed
18LORD, ABBETT & CO. LLC$68.1M32,829Trimmed
19AMERICAN CENTURY COMPANIES INC$64.5M31,108Added
20NORGES BANK$58.0M27,956Trimmed
21Cannell & Spears LLC$57.2M27,577Trimmed
22BANK OF AMERICA CORP /DE/$51.9M25,028Trimmed
23CHARLES SCHWAB INVESTMENT MANAGEMENT INC$48.7M23,505Trimmed
24Sixth Street Partners Management Company, L.P.$48.7M23,505New
25Mraz, Amerine & Associates, Inc.$46.1M22,218Added

Source: SEC Form 13F filings · as of 2026-06-30