White Mountains Insurance Group Ltd
WTM- Exchange
- NYSE
- Industry
- Fire, Marine & Casualty Insurance
- SEC CIK
- 0000776867
No open-market purchases or sales by White Mountains Insurance Group Ltd insiders were filed in the last 90 days; 356 institutions reported holding it in 13F filings for Q2 2026, worth $4.57B in total; Southeastern Asset Management (Longleaf) is the only superinvestor holding it.
13F holders, Q4 2025
Institutional positions in White Mountains Insurance Group Ltd as of Dec 31, 2025. Investment managers with $100 million or more in US stocks report their long positions on Form 13F within 45 days after each quarter ends. How 13F works
- Institutional holders
- 353
- +20 vs. Q3 2025
- Shares held
- 2.25M
- −77.3K (−3.3%) vs. Q3 2025
- Total value
- $4.67B
- +$782.8M (+20.1%) vs. Q3 2025
- New holders
- 55
- 104 more added
- Sold out
- 35
- 126 more reduced
5 institutions that held it in Q3 2025 haven't filed for Q4 2025 yet. Not filing isn't selling, so they aren't counted as sold out or in the changes above.
Compare with Q3 2025: new holders, sold out and not filed yet
Holders and value by quarter
Institutions reporting WTM on Form 13F each quarter since Q1 2021, and the total value they reported. Values are as of each quarter end, so they also move with the share price.
| Quarter | Holders | Value |
|---|---|---|
| Q2 2026 | 356 | $4.57B |
| Q1 2026 | 368 | $4.86B |
| Q4 2025 | 353 | $4.67B |
| Q3 2025 | 338 | $3.89B |
| Q2 2025 | 325 | $4.17B |
| Q1 2025 | 322 | $4.44B |
| Q4 2024 | 325 | $4.43B |
| Q3 2024 | 304 | $3.78B |
| Q2 2024 | 306 | $4.14B |
| Q1 2024 | 303 | $4.06B |
| Q4 2023 | 295 | $3.42B |
| Q3 2023 | 272 | $3.40B |
| Q2 2023 | 258 | $3.13B |
| Q1 2023 | 262 | $3.09B |
| Q4 2022 | 265 | $3.20B |
| Q3 2022 | 251 | $2.98B |
| Q2 2022 | 259 | $3.32B |
| Q1 2022 | 244 | $3.09B |
| Q4 2021 | 243 | $2.71B |
| Q3 2021 | 232 | $2.86B |
| Q2 2021 | 233 | $3.11B |
| Q1 2021 | 245 | $3.02B |
Institutions, Q4 2025
Shares, value and share of portfolio for each institution holding White Mountains Insurance Group Ltd; share changes are against Q3 2025.
| Institution | Shares | Value | % of portfolio | Change in shares | Action |
|---|---|---|---|---|---|
| Williams Jones Wealth Management, LLC. | 5,193 | $10.8M | 0.12% | 00.0% | Unchanged |
| Goldman Sachs Group Inc | 5,260 | $10.9M | 0.00% | −651−11.0% | Reduced |
| Bradley Foster & Sargent Inc | 5,456 | $11.3M | 0.17% | −90−1.6% | Reduced |
| Phocas Financial Corp. | 5,491 | $11.4M | 1.48% | −14−0.3% | Reduced |
| Royce & Associates LP | 5,947 | $12.4M | 0.13% | −355−5.6% | Reduced |
| UBS Group AG | 6,001 | $12.5M | 0.00% | −6,084−50.3% | Reduced |
| Victory Capital Management Inc | 6,296 | $13.1M | 0.01% | −2,230−26.2% | Reduced |
| California Public Employees Retirement System | 6,716 | $14.0M | 0.01% | −2,516−27.3% | Reduced |
| Gotham Asset Management, LLC | 6,716 | $14.0M | 0.05% | −183−2.7% | Reduced |
| Hotchkis & Wiley Capital Management LLC | 6,752 | $14.0M | 0.04% | −354−5.0% | Reduced |
| Quantinno Capital Management LP | 7,271 | $15.1M | 0.03% | +1,217+20.1% | Added |
| UBS Asset Management Americas Inc | 7,655 | $15.9M | 0.00% | +7,648+109,257.1% | Added |
| SEI Investments Co | 7,916 | $16.5M | 0.02% | +2,530+47.0% | Added |
| D. E. Shaw & Co., Inc. | 8,593 | $17.9M | 0.01% | +6,081+242.1% | Added |
| GW&K Investment Management, LLC | 8,621 | $17.9M | 0.15% | +611+7.6% | Added |
| Bank of New York Mellon Corp | 8,831 | $18.4M | 0.00% | −1,271−12.6% | Reduced |
| Thompson Siegel & Walmsley LLC | 8,927 | $18.6M | 0.31% | +275+3.2% | Added |
| Wells Fargo & Company | 9,141 | $19.0M | 0.00% | −211−2.3% | Reduced |
| Speece Thorson Capital Group Inc | 10,672 | $22.2M | 4.80% | −590−5.2% | Reduced |
| WCM Investment Management, LLC | 10,682 | $22.2M | 0.05% | −2,553−19.3% | Reduced |
| Horizon Kinetics Asset Management LLC | 13,121 | $27.3M | 0.37% | +37+0.3% | Added |
| Elkhorn Partners Limited Partnership | 13,598 | $28.3M | 17.85% | −1,212−8.2% | Reduced |
| Envestnet Asset Management Inc | 15,798 | $32.8M | 0.01% | −1,793−10.2% | Reduced |
| Wellington Management Group LLP | 15,928 | $33.1M | 0.01% | −3,283−17.1% | Reduced |
| Northern Trust Corp | 16,667 | $34.6M | 0.00% | −1,090−6.1% | Reduced |
| Brown Advisory Inc | 18,956 | $39.4M | 0.05% | −1,376−6.8% | Reduced |
| Select Equity Group, L.P. | 19,713 | $41.0M | 0.19% | +2,767+16.3% | Added |
| Allspring Global Investments Holdings, LLC | 20,193 | $41.2M | 0.07% | −11,505−36.3% | Reduced |
| Mraz, Amerine & Associates, Inc. | 22,629 | $47.0M | 6.99% | +23+0.1% | Added |
| Charles Schwab Investment Management Inc | 23,238 | $48.3M | 0.01% | −994−4.1% | Reduced |
| Raymond James Financial Inc | 23,969 | $49.8M | 0.02% | −5,423−18.5% | Reduced |
| Spears Abacus Advisors LLC | 28,115 | $58.4M | 1.09% | −173−0.6% | Reduced |
| Bank of America Corp | 28,809 | $59.9M | 0.00% | −10,003−25.8% | Reduced |
| Southeastern Asset Management IncSuperinvestorSoutheastern Asset Management (Longleaf) | 31,652 | $65.8M | 2.93% | 00.0% | Unchanged |
| Norges Bank | 32,184 | $66.9M | 0.01% | +32,184 | New |
| Gendell Jeffrey L | 32,520 | $67.6M | 1.18% | +32,520 | New |
| Lord, Abbett & Co. LLC | 33,796 | $70.2M | 0.22% | −3,123−8.5% | Reduced |
| Geode Capital Management, LLC | 41,518 | $86.3M | 0.01% | −572−1.4% | Reduced |
| Reinhart Partners, Inc. | 43,973 | $91.4M | 2.74% | +2,364+5.7% | Added |
| T. Rowe Price Investment Management, Inc. | 44,560 | $92.6M | 0.06% | −3,212−6.7% | Reduced |
| State Street Corp | 50,663 | $105.3M | 0.00% | −3,781−6.9% | Reduced |
| London Co of Virginia | 58,697 | $122.0M | 0.70% | −8,105−12.1% | Reduced |
| Boston Partners | 76,911 | $159.7M | 0.17% | −7,534−8.9% | Reduced |
| Wallace Capital Management Inc. | 80,347 | $167.0M | 20.10% | −1,142−1.4% | Reduced |
| Morgan Stanley | 82,151 | $170.7M | 0.01% | −56,711−40.8% | Reduced |
| Fiduciary Management Inc | 90,333 | $187.7M | 2.06% | −4,050−4.3% | Reduced |
| Cooke & Bieler LP | 106,579 | $221.5M | 2.31% | −1,272−1.2% | Reduced |
| Fuller & Thaler Asset Management, Inc. | 108,172 | $224.8M | 0.76% | +81+0.1% | Added |
| BlackRock, Inc. | 112,289 | $233.3M | 0.00% | −290−0.3% | Reduced |
| River Road Asset Management, LLC | 120,880 | $251.2M | 2.76% | +11,292+10.3% | Added |
| Neuberger Berman Group LLC | 129,654 | $269.4M | 0.20% | +14,639+12.7% | Added |
| Dimensional Fund Advisors LP | 156,604 | $325.4M | 0.07% | −613−0.4% | Reduced |
| Vanguard Group Inc | 235,698 | $489.8M | 0.01% | −11,306−4.6% | Reduced |
| Perpetual Ltd | 0 | $0 | 0.00% | −8,127−100.0% | Sold out |
| Lighthouse Investment Partners, LLC | 0 | $0 | 0.00% | −2,939−100.0% | Sold out |
| Oddo BHF Asset Management SAS | 0 | $0 | 0.00% | −930−100.0% | Sold out |
| Magnetar Financial LLC | 0 | $0 | 0.00% | −881−100.0% | Sold out |
| ExodusPoint Capital Management, LP | 0 | $0 | 0.00% | −401−100.0% | Sold out |
| Walleye Capital LLC | 0 | $0 | 0.00% | −396−100.0% | Sold out |
| QRG Capital Management, Inc. | 0 | $0 | 0.00% | −369−100.0% | Sold out |
| Capstone Investment Advisors, LLC | 0 | $0 | 0.00% | −368−100.0% | Sold out |
| Teacher Retirement System of Texas | 0 | $0 | 0.00% | −337−100.0% | Sold out |
| Farringdon Capital, Ltd. | 0 | $0 | 0.00% | −310−100.0% | Sold out |
| Virtu Financial LLC | 0 | $0 | 0.00% | −309−100.0% | Sold out |
| Balyasny Asset Management LLC | 0 | $0 | 0.00% | −298−100.0% | Sold out |
| National Wealth Management Group, LLC | 0 | $0 | 0.00% | −208−100.0% | Sold out |
| SummitTX Capital, L.P. | 0 | $0 | 0.00% | −200−100.0% | Sold out |
| Neville Rodie & Shaw Inc | 0 | $0 | 0.00% | −200−100.0% | Sold out |
| Susquehanna Portfolio Strategies, LLC | 0 | $0 | 0.00% | −187−100.0% | Sold out |
| Inceptionr LLC | 0 | $0 | 0.00% | −185−100.0% | Sold out |
| Marex Group plc | 0 | $0 | 0.00% | −163−100.0% | Sold out |
| Prudential Financial Inc | 0 | $0 | 0.00% | −156−100.0% | Sold out |
| Freestone Grove Partners LP | 0 | $0 | 0.00% | −144−100.0% | Sold out |
| Requisite Capital Management, LLC | 0 | $0 | 0.00% | −129−100.0% | Sold out |
| Roehl & Yi Investment Advisors, LLC | 0 | $0 | 0.00% | −120−100.0% | Sold out |
| Macquarie Group Ltd | 0 | $0 | 0.00% | −107−100.0% | Sold out |
| Advisory Services Network, LLC | 0 | $0 | 0.00% | −45−100.0% | Sold out |
| Ameriflex Group, Inc. | 0 | $0 | 0.00% | −20−100.0% | Sold out |
| Wealthspire Advisors, LLC | 0 | $0 | 0.00% | −9−100.0% | Sold out |
| Bayforest Capital Ltd | 0 | $0 | 0.00% | −9−100.0% | Sold out |
| NBC Securities, Inc. | 0 | $0 | 0.00% | −7−100.0% | Sold out |
| Proffitt & Goodson Inc | 0 | $0 | 0.00% | −6−100.0% | Sold out |
| Premier Fund Managers Ltd | 0 | $0 | 0.00% | −5−100.0% | Sold out |
| Spire Wealth Management | 0 | $0 | 0.00% | −3−100.0% | Sold out |
| Tortoise Investment Management, LLC | 0 | $0 | 0.00% | −1−100.0% | Sold out |
| Atlantic Trust, LLC | 0 | $0 | 0.00% | −1−100.0% | Sold out |
| SBI Securities Co., Ltd. | 0 | $0 | 0.00% | −1−100.0% | Sold out |
| Cloud Capital Management, LLC | 0 | $0 | 0.00% | −1−100.0% | Sold out |
| Cove Street Capital, LLC | – | – | – | – | Not filed |
| Kathleen S. Wright Associates Inc. | – | – | – | – | Not filed |
| Glenmede Investment Management, LP | – | – | – | – | Not filed |
| Hemington Wealth Management | – | – | – | – | Not filed |
| Binnacle Investments Inc | – | – | – | – | Not filed |