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, Q2 2026
Institutional positions in White Mountains Insurance Group Ltd as of Jun 30, 2026. 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
- 356
- −7 vs. Q1 2026
- Shares held
- 2.20M
- +8.83K (+0.4%) vs. Q1 2026
- Total value
- $4.57B
- −$252.8M (−5.2%) vs. Q1 2026
- New holders
- 39
- 96 more added
- Sold out
- 46
- 146 more reduced
5 institutions that held it in Q1 2026 haven't filed for Q2 2026 yet. Not filing isn't selling, so they aren't counted as sold out or in the changes above.
Compare with Q1 2026: 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 | $4.91B |
| Q3 2025 | 338 | $3.90B |
| Q2 2025 | 325 | $4.17B |
| Q1 2025 | 322 | $4.44B |
| Q4 2024 | 325 | $4.43B |
| Q3 2024 | 304 | $3.78B |
| Q2 2024 | 306 | $4.20B |
| Q1 2024 | 303 | $4.78B |
| Q4 2023 | 295 | $3.76B |
| Q3 2023 | 272 | $3.43B |
| Q2 2023 | 258 | $3.16B |
| Q1 2023 | 262 | $3.14B |
| Q4 2022 | 265 | $3.20B |
| Q3 2022 | 252 | $2.98B |
| Q2 2022 | 259 | $3.32B |
| Q1 2022 | 244 | $3.09B |
| Q4 2021 | 243 | $2.72B |
| Q3 2021 | 232 | $2.86B |
| Q2 2021 | 233 | $3.11B |
| Q1 2021 | 245 | $3.03B |
Institutions, Q2 2026
Shares, value and share of portfolio for each institution holding White Mountains Insurance Group Ltd; share changes are against Q1 2026.
| Institution | Shares | Value | % of portfolio | Change in shares | Action |
|---|---|---|---|---|---|
| Dimensional Fund Advisors LP | 158,954 | $329.6M | 0.06% | +2,336+1.5% | Added |
| Neuberger Berman Group LLC | 119,141 | $247.0M | 0.16% | −5,574−4.5% | Reduced |
| BlackRock, Inc. | 117,871 | $244.4M | 0.00% | +4,543+4.0% | Added |
| River Road Asset Management, LLC | 115,880 | $240.3M | 2.67% | −4,639−3.8% | Reduced |
| Vanguard Portfolio Management LLC | 111,969 | $232.2M | 0.01% | −3,584−3.1% | Reduced |
| Vanguard Capital Management LLC | 107,479 | $222.8M | 0.00% | −1,678−1.5% | Reduced |
| Fuller & Thaler Asset Management, Inc. | 101,892 | $211.3M | 0.58% | −2,669−2.6% | Reduced |
| Cooke & Bieler LP | 85,120 | $176.5M | 2.04% | −19,737−18.8% | Reduced |
| Wallace Capital Management Inc. | 80,067 | $166.0M | 18.20% | +1,272+1.6% | Added |
| Fiduciary Management Inc | 66,550 | $138.0M | 1.96% | −18,516−21.8% | Reduced |
| Gendell Jeffrey L | 59,243 | $122.8M | 1.11% | +21,429+56.7% | Added |
| Boston Partners | 55,569 | $115.3M | 0.10% | −1,890−3.3% | Reduced |
| London Co of Virginia | 54,025 | $112.1M | 0.64% | −3,106−5.4% | Reduced |
| State Street Corp | 50,257 | $104.2M | 0.00% | +1,099+2.2% | Added |
| Geode Capital Management, LLC | 49,412 | $102.5M | 0.01% | +7,293+17.3% | Added |
| Morgan Stanley | 46,866 | $97.2M | 0.01% | −12,429−21.0% | Reduced |
| Reinhart Partners, Inc. | 44,480 | $92.3M | 2.11% | +7,106+19.0% | Added |
| T. Rowe Price Investment Management, Inc. | 34,237 | $71.0M | 0.05% | −7,276−17.5% | Reduced |
| Lord, Abbett & Co. LLC | 32,829 | $68.1M | 0.19% | −281−0.8% | Reduced |
| American Century Companies Inc | 31,108 | $64.5M | 0.03% | +22,800+274.4% | Added |
| Norges Bank | 27,956 | $58.0M | 0.01% | +27,956 | New |
| Spears Abacus Advisors LLC | 27,577 | $57.2M | 1.02% | −450−1.6% | Reduced |
| Bank of America Corp | 25,028 | $51.9M | 0.00% | −3,330−11.7% | Reduced |
| Charles Schwab Investment Management Inc | 23,505 | $48.7M | 0.01% | −736−3.0% | Reduced |
| Mraz, Amerine & Associates, Inc. | 22,218 | $46.1M | 6.61% | +39+0.2% | Added |
| Allspring Global Investments Holdings, LLC | 18,116 | $37.4M | 0.06% | −496−2.7% | Reduced |
| Gotham Asset Management, LLC | 17,940 | $37.2M | 0.09% | +8,893+98.3% | Added |
| Brown Advisory Inc | 17,722 | $36.7M | 0.06% | −122−0.7% | Reduced |
| Jane Street Group, LLC | 17,226 | $35.7M | 0.02% | +3,418+24.8% | Added |
| Southeastern Asset Management IncSuperinvestorSoutheastern Asset Management (Longleaf) | 17,104 | $35.5M | 1.85% | −1,760−9.3% | Reduced |
| UBS Group AG | 16,198 | $33.6M | 0.01% | +5,757+55.1% | Added |
| Vanguard Fiduciary Trust Co | 15,319 | $31.8M | 0.01% | +133+0.9% | Added |
| Raymond James Financial Inc | 14,833 | $30.8M | 0.01% | −9,118−38.1% | Reduced |
| Northern Trust Corp | 14,571 | $30.2M | 0.00% | −924−6.0% | Reduced |
| Wellington Management Group LLP | 14,532 | $30.1M | 0.01% | −352−2.4% | Reduced |
| Envestnet Asset Management Inc | 13,838 | $28.7M | 0.01% | −1,725−11.1% | Reduced |
| Quantinno Capital Management LP | 12,624 | $26.2M | 0.03% | +2,840+29.0% | Added |
| Elkhorn Partners Limited Partnership | 12,320 | $25.5M | 21.89% | −380−3.0% | Reduced |
| Horizon Kinetics Asset Management LLC | 12,206 | $25.3M | 0.29% | −906−6.9% | Reduced |
| Goldman Sachs Group Inc | 12,151 | $25.2M | 0.00% | −3,632−23.0% | Reduced |
| Boussard & Gavaudan Gestion SAS | 11,679 | $24.5M | 1.24% | +11,679 | New |
| Victory Capital Management Inc | 10,684 | $22.2M | 0.01% | −461−4.1% | Reduced |
| First Trust Advisors LP | 10,604 | $22.0M | 0.01% | +7,546+246.8% | Added |
| Qube Research & Technologies Ltd | 9,673 | $20.1M | 0.02% | +8,657+852.1% | Added |
| Speece Thorson Capital Group Inc | 9,215 | $19.1M | 4.08% | −182−1.9% | Reduced |
| Wells Fargo & Company | 8,710 | $18.1M | 0.00% | −72−0.8% | Reduced |
| Bank of New York Mellon Corp | 8,412 | $17.4M | 0.00% | −32−0.4% | Reduced |
| SEI Investments Co | 8,108 | $16.8M | 0.01% | −2,990−26.9% | Reduced |
| GW&K Investment Management, LLC | 7,839 | $16.3M | 0.13% | −87−1.1% | Reduced |
| Thompson Siegel & Walmsley LLC | 7,656 | $15.9M | 0.29% | +447+6.2% | Added |
| Arrowstreet Capital, Limited Partnership | 7,284 | $15.1M | 0.01% | +5,371+280.8% | Added |
| Citadel Advisors LLC | 7,136 | $14.8M | 0.01% | +4,533+174.1% | Added |
| Hotchkis & Wiley Capital Management LLC | 6,788 | $14.1M | 0.04% | +740+12.2% | Added |
| Royce & Associates LP | 6,781 | $14.1M | 0.11% | +321+5.0% | Added |
| HRT Financial LP | 6,760 | $14.0M | 0.03% | +4,385+184.6% | Added |
| D. E. Shaw & Co., Inc. | 6,618 | $13.7M | 0.01% | −2,292−25.7% | Reduced |
| Edgestream Partners, L.P. | 6,578 | $13.6M | 0.41% | +3,448+110.2% | Added |
| JPMorgan Chase & Co | 5,410 | $11.5M | 0.00% | +2,843+110.8% | Added |
| AQR Capital Management LLC | 5,450 | $11.3M | 0.00% | −2,288−29.6% | Reduced |
| California Public Employees Retirement System | 5,248 | $10.9M | 0.01% | −1,166−18.2% | Reduced |
| Williams Jones Wealth Management, LLC. | 5,193 | $10.8M | 0.12% | −10.0% | Reduced |
| Swiss National Bank | 4,826 | $10.0M | 0.01% | −210−4.2% | Reduced |
| Winmill & Co. Inc | 4,800 | $9.95M | 2.20% | +4,800 | New |
| Franklin Resources Inc | 4,178 | $8.66M | 0.00% | −620−12.9% | Reduced |
| Phocas Financial Corp. | 4,078 | $8.46M | 1.17% | −214−5.0% | Reduced |
| Rhumbline Advisers | 3,898 | $8.08M | 0.01% | −234−5.7% | Reduced |
| Creative Planning | 3,861 | $8.01M | 0.00% | −188−4.6% | Reduced |
| Nuveen, LLC | 3,679 | $7.63M | 0.00% | −630−14.6% | Reduced |
| Invesco Ltd. | 3,497 | $7.25M | 0.00% | +530+17.9% | Added |
| Lee Danner & Bass Inc | 3,253 | $6.74M | 0.39% | +50+1.6% | Added |
| Ameriprise Financial Inc | 2,852 | $5.91M | 0.00% | −14−0.5% | Reduced |
| California State Teachers Retirement System | 2,761 | $5.72M | 0.01% | −126−4.4% | Reduced |
| New York State Common Retirement Fund | 2,532 | $5.25M | 0.01% | +19+0.8% | Added |
| Triad Investment Management | 2,471 | $5.12M | 5.65% | −42−1.7% | Reduced |
| Vanguard Asset Management, Ltd | 2,392 | $4.96M | 0.00% | +67+2.9% | Added |
| Russell Investments Group, Ltd. | 2,369 | $4.91M | 0.00% | +1,227+107.4% | Added |
| State Board of Administration of Florida Retirement System | 2,351 | $4.87M | 0.01% | +90+4.0% | Added |
| Price T Rowe Associates Inc | 2,335 | $4.84M | 0.00% | +124+5.6% | Added |
| Legal & General Group Plc | 2,257 | $4.68M | 0.00% | −151−6.3% | Reduced |
| Robeco Institutional Asset Management B.V. | 2,184 | $4.53M | 0.01% | +5+0.2% | Added |
| Regency Capital Management Inc. | 2,146 | $4.45M | 1.77% | +611+39.8% | Added |
| Davenport & Co LLC | 2,123 | $4.40M | 0.02% | 00.0% | Unchanged |
| Bradley Foster & Sargent Inc | 1,899 | $3.94M | 0.06% | −103−5.1% | Reduced |
| Parsons Capital Management Inc | 1,887 | $3.91M | 0.18% | −1−0.1% | Reduced |
| Lighthouse Investment Partners, LLC | 1,868 | $3.87M | 0.12% | +1,868 | New |
| Cerity Partners LLC | 1,797 | $3.73M | 0.00% | −70−3.7% | Reduced |
| Atlantic Union Bankshares Corp | 1,765 | $3.66M | 0.06% | 00.0% | Unchanged |
| MML Investors Services, LLC | 1,741 | $3.61M | 0.01% | −718−29.2% | Reduced |
| Agf Management Ltd | 1,696 | $3.52M | 0.01% | −7−0.4% | Reduced |
| XTX Topco Ltd | 1,644 | $3.41M | 0.04% | +1,394+557.6% | Added |
| Toroso Investments, LLC | 1,578 | $3.27M | 0.01% | +230+17.1% | Added |
| Colony Group, LLC | 1,553 | $3.22M | 0.00% | +424+37.6% | Added |
| ExodusPoint Capital Management, LP | 1,443 | $2.99M | 0.03% | +832+136.2% | Added |
| Oppenheimer Asset Management Inc. | 1,356 | $2.81M | 0.03% | −124−8.4% | Reduced |
| LPL Financial LLC | 1,318 | $2.73M | 0.00% | −77−5.5% | Reduced |
| HighTower Advisors, LLC | 1,316 | $2.73M | 0.00% | −131−9.1% | Reduced |
| Royal Bank of Canada | 1,237 | $2.57M | 0.00% | +42+3.5% | Added |
| Stifel Financial Corp | 1,235 | $2.56M | 0.00% | −59−4.6% | Reduced |
| WCM Investment Management, LLC | 1,197 | $2.50M | 0.00% | −4,798−80.0% | Reduced |
| Northern Oak Wealth Management Inc | 1,176 | $2.44M | 0.28% | 00.0% | Unchanged |