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, Q1 2026
Institutional positions in White Mountains Insurance Group Ltd as of Mar 31, 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
- 368
- +23 vs. Q4 2025
- Shares held
- 2.21M
- +232.8K (+11.8%) vs. Q4 2025
- Total value
- $4.86B
- +$748.7M (+18.2%) vs. Q4 2025
- New holders
- 49
- 120 more added
- Sold out
- 26
- 111 more reduced
8 institutions that held it in Q4 2025 haven't filed for Q1 2026 yet. Not filing isn't selling, so they aren't counted as sold out or in the changes above.
Compare with Q4 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, Q1 2026
Shares, value and share of portfolio for each institution holding White Mountains Insurance Group Ltd; share changes are against Q4 2025.
| Institution | Shares | Value | % of portfolio | Change in shares | Action |
|---|---|---|---|---|---|
| Bank of Montreal | 433 | $951.3K | 0.00% | +2+0.5% | Added |
| Main Street Financial Solutions, LLC | 439 | $963.4K | 0.07% | −396−47.4% | Reduced |
| Resona Asset Management Co.,Ltd. | 443 | $973.3K | 0.00% | 00.0% | Unchanged |
| Legacy Advisors, LLC | 450 | $988.6K | 0.12% | 00.0% | Unchanged |
| Pathstone Holdings, LLC | 460 | $1.01M | 0.00% | +5+1.1% | Added |
| Entropy Technologies, LP | 470 | $1.03M | 0.05% | −20−4.1% | Reduced |
| Parker Investment Management, LLC | 475 | $1.04M | 0.16% | 00.0% | Unchanged |
| Chicago Partners Investment Group LLC | 467 | $1.06M | 0.02% | −56−10.7% | Reduced |
| Janney Montgomery Scott LLC | 510 | $1.12M | 0.00% | +28+5.8% | Added |
| Regions Financial Corp | 517 | $1.14M | 0.01% | −275−34.7% | Reduced |
| Lexington Hill Partners, LLC | 520 | $1.14M | 0.65% | +520 | New |
| B.O.S.S. Retirement Advisors, LLC | 533 | $1.17M | 0.36% | 00.0% | Unchanged |
| Barclays PLC | 535 | $1.18M | 0.00% | −24−4.3% | Reduced |
| The PNC Financial Services Group, Inc. | 546 | $1.20M | 0.00% | +10+1.9% | Added |
| Sendero Wealth Management, LLC | 562 | $1.23M | 0.14% | 00.0% | Unchanged |
| KLP Kapitalforvaltning AS | 565 | $1.24M | 0.00% | −30−5.0% | Reduced |
| AMG National Trust Bank | 571 | $1.25M | 0.03% | −24−4.0% | Reduced |
| Allstate Corp | 581 | $1.28M | 0.01% | +581 | New |
| Wiley Bros.-Aintree Capital, LLC | 598 | $1.31M | 0.01% | −40−6.3% | Reduced |
| Mariner, LLC | 607 | $1.33M | 0.00% | +205+51.0% | Added |
| ExodusPoint Capital Management, LP | 611 | $1.34M | 0.01% | +611 | New |
| Manufacturers Life Insurance Company, The | 614 | $1.35M | 0.00% | +59+10.6% | Added |
| Amundi | 615 | $1.35M | 0.00% | +615 | New |
| Nelson, Van Denburg & Campbell Wealth Management Group, LLC | 617 | $1.36M | 0.04% | 00.0% | Unchanged |
| Vanguard Investments Australia, Ltd. | 623 | $1.37M | 0.00% | +623 | New |
| Advisor Group Holdings, Inc. | 650 | $1.43M | 0.00% | +240+58.5% | Added |
| Farther Finance Advisors, LLC | 656 | $1.43M | 0.01% | +86+15.1% | Added |
| Truist Financial Corp | 684 | $1.50M | 0.00% | −52−7.1% | Reduced |
| Texas Yale Capital Corp. | 687 | $1.51M | 0.04% | 00.0% | Unchanged |
| Brandes Investment Partners, LP | 698 | $1.53M | 0.01% | +33+5.0% | Added |
| Arizona State Retirement System | 699 | $1.54M | 0.01% | −19−2.6% | Reduced |
| Park Avenue Securities LLC | 703 | $1.54M | 0.01% | −58−7.6% | Reduced |
| Fieldview Capital Management, LLC | 729 | $1.60M | 0.47% | +729 | New |
| Nisa Investment Advisors, LLC | 738 | $1.62M | 0.01% | +4+0.5% | Added |
| Public Employees Retirement System of Ohio | 751 | $1.65M | 0.01% | −25−3.2% | Reduced |
| Summit Trail Advisors, LLC | 760 | $1.67M | 0.02% | +160+26.7% | Added |
| Teachers Retirement System of the State of Kentucky | 767 | $1.69M | 0.01% | 00.0% | Unchanged |
| Ethic Inc. | 800 | $1.76M | 0.03% | +128+19.0% | Added |
| Private Management Group Inc | 823 | $1.81M | 0.05% | +97+13.4% | Added |
| Sequoia Financial Advisors, LLC | 824 | $1.81M | 0.01% | −82−9.1% | Reduced |
| Equitable Trust Co | 830 | $1.82M | 0.08% | −10−1.2% | Reduced |
| Mercer Global Advisors Inc | 866 | $1.90M | 0.00% | +151+21.1% | Added |
| Handelsbanken Fonder AB | 880 | $1.93M | 0.01% | 00.0% | Unchanged |
| Alliancebernstein L.P. | 953 | $1.98M | 0.00% | +146+18.1% | Added |
| FMR LLC | 905 | $1.99M | 0.00% | −34−3.6% | Reduced |
| Aquatic Capital Management LLC | 912 | $2.00M | 0.06% | −268−22.7% | Reduced |
| Zurcher Kantonalbank (Zurich Cantonalbank) | 913 | $2.01M | 0.00% | 00.0% | Unchanged |
| Capula Management Ltd | 921 | $2.02M | 0.02% | +921 | New |
| Brave Asset Management Inc | 924 | $2.03M | 0.48% | 00.0% | Unchanged |
| TD Asset Management Inc | 932 | $2.05M | 0.00% | −68−6.8% | Reduced |
| Vanguard Global Advisers, LLC | 1,002 | $2.20M | 0.00% | +1,002 | New |
| O'Shaughnessy Asset Management, LLC | 1,010 | $2.22M | 0.01% | +76+8.1% | Added |
| Qube Research & Technologies Ltd | 1,016 | $2.23M | 0.00% | +484+91.0% | Added |
| Harbor Capital Advisors, Inc. | 1,038 | $2.28M | 0.18% | +174+20.1% | Added |
| Leuthold Group, LLC | 1,052 | $2.31M | 0.25% | −65−5.8% | Reduced |
| Treasurer of the State of North Carolina | 1,056 | $2.32M | 0.01% | +22+2.1% | Added |
| Autumn Glory Partners, LLC | 1,080 | $2.37M | 0.87% | 00.0% | Unchanged |
| Police & Firemen's Retirement System of New Jersey | 1,082 | $2.38M | 0.02% | +12+1.1% | Added |
| Janus Henderson Group PLC | 1,123 | $2.46M | 0.00% | 00.0% | Unchanged |
| State of New Jersey Common Pension Fund D | 1,135 | $2.49M | 0.01% | 00.0% | Unchanged |
| Russell Investments Group, Ltd. | 1,142 | $2.51M | 0.00% | +745+187.7% | Added |
| Diversified Management Inc | 1,158 | $2.54M | 0.44% | +1,158 | New |
| Pecaut & Co. | 1,172 | $2.57M | 0.84% | +5+0.4% | Added |
| Northern Oak Wealth Management Inc | 1,176 | $2.58M | 0.32% | 00.0% | Unchanged |
| Royal Bank of Canada | 1,195 | $2.63M | 0.00% | +98+8.9% | Added |
| Quadrature Capital Ltd | 1,213 | $2.66M | 0.03% | +853+236.9% | Added |
| Captrust Financial Advisors | 1,235 | $2.71M | 0.00% | +530+75.2% | Added |
| Empowered Funds, LLC | 1,284 | $2.82M | 0.02% | +1,284 | New |
| Stifel Financial Corp | 1,294 | $2.84M | 0.00% | −18−1.4% | Reduced |
| Toroso Investments, LLC | 1,348 | $2.96M | 0.01% | +1,144+560.8% | Added |
| CI Private Wealth, LLC | 1,398 | $3.02M | 0.00% | +492+54.3% | Added |
| LPL Financial LLC | 1,395 | $3.07M | 0.00% | −570−29.0% | Reduced |
| Citigroup Inc | 1,400 | $3.08M | 0.00% | −449−24.3% | Reduced |
| HighTower Advisors, LLC | 1,447 | $3.18M | 0.00% | 00.0% | Unchanged |
| Oppenheimer Asset Management Inc. | 1,480 | $3.25M | 0.04% | −22−1.5% | Reduced |
| Regency Capital Management Inc. | 1,535 | $3.37M | 1.51% | −100−6.1% | Reduced |
| Agf Management Ltd | 1,703 | $3.74M | 0.02% | +295+21.0% | Added |
| Colony Group, LLC | 1,129 | $3.82M | 0.00% | −481−29.9% | Reduced |
| Atlantic Union Bankshares Corp | 1,765 | $3.88M | 0.07% | 00.0% | Unchanged |
| Cerity Partners LLC | 1,867 | $4.10M | 0.01% | −1,676−47.3% | Reduced |
| Parsons Capital Management Inc | 1,888 | $4.15M | 0.19% | +16+0.9% | Added |
| Arrowstreet Capital, Limited Partnership | 1,913 | $4.20M | 0.00% | +1,102+135.9% | Added |
| Bradley Foster & Sargent Inc | 2,002 | $4.40M | 0.07% | −3,454−63.3% | Reduced |
| Davenport & Co LLC | 2,123 | $4.66M | 0.03% | 00.0% | Unchanged |
| Robeco Institutional Asset Management B.V. | 2,179 | $4.79M | 0.01% | +1,556+249.8% | Added |
| Price T Rowe Associates Inc | 2,211 | $4.86M | 0.00% | +221+11.1% | Added |
| Dark Forest Capital Management LP | 2,255 | $4.95M | 0.44% | −1,360−37.6% | Reduced |
| State Board of Administration of Florida Retirement System | 2,261 | $4.97M | 0.01% | −531−19.0% | Reduced |
| Vanguard Asset Management, Ltd | 2,325 | $5.11M | 0.00% | +2,325 | New |
| HRT Financial LP | 2,375 | $5.22M | 0.01% | +2,242+1,685.7% | Added |
| Legal & General Group Plc | 2,408 | $5.29M | 0.00% | −629−20.7% | Reduced |
| MML Investors Services, LLC | 2,459 | $5.40M | 0.01% | −476−16.2% | Reduced |
| Triad Investment Management | 2,513 | $5.52M | 6.52% | −35−1.4% | Reduced |
| New York State Common Retirement Fund | 2,513 | $5.52M | 0.01% | 00.0% | Unchanged |
| JPMorgan Chase & Co | 2,567 | $5.63M | 0.00% | +761+42.1% | Added |
| Citadel Advisors LLC | 2,603 | $5.72M | 0.00% | +1,410+118.2% | Added |
| Renaissance Technologies LLC | 2,611 | $5.74M | 0.01% | +1,110+74.0% | Added |
| Ameriprise Financial Inc | 2,866 | $6.30M | 0.00% | −187−6.1% | Reduced |
| California State Teachers Retirement System | 2,887 | $6.34M | 0.01% | +430+17.5% | Added |
| Invesco Ltd. | 2,967 | $6.52M | 0.00% | −28−0.9% | Reduced |