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 2025
Institutional positions in White Mountains Insurance Group Ltd as of Jun 30, 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
- 325
- +7 vs. Q1 2025
- Shares held
- 2.32M
- +12.3K (+0.5%) vs. Q1 2025
- Total value
- $4.17B
- −$275.8M (−6.2%) vs. Q1 2025
- New holders
- 33
- 103 more added
- Sold out
- 26
- 112 more reduced
4 institutions that held it in Q1 2025 haven't filed for Q2 2025 yet. Not filing isn't selling, so they aren't counted as sold out or in the changes above.
Compare with Q1 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, Q2 2025
Shares, value and share of portfolio for each institution holding White Mountains Insurance Group Ltd; share changes are against Q1 2025.
| Institution | Shares | Value | % of portfolio | Change in shares | Action |
|---|---|---|---|---|---|
| Mraz, Amerine & Associates, Inc. | 21,576 | $38.7M | 6.21% | +548+2.6% | Added |
| Charles Schwab Investment Management Inc | 24,183 | $43.4M | 0.01% | −523−2.1% | Reduced |
| Wellington Management Group LLP | 24,651 | $44.3M | 0.01% | −787−3.1% | Reduced |
| Spears Abacus Advisors LLC | 28,347 | $50.9M | 1.03% | −321−1.1% | Reduced |
| Allspring Global Investments Holdings, LLC | 29,585 | $53.0M | 0.09% | +4,728+19.0% | Added |
| Norges Bank | 30,494 | $54.8M | 0.01% | −476−1.5% | Reduced |
| Raymond James Financial Inc | 30,677 | $55.1M | 0.02% | −1,047−3.3% | Reduced |
| Lord, Abbett & Co. LLC | 32,227 | $57.9M | 0.19% | −624−1.9% | Reduced |
| Bank of America Corp | 39,409 | $70.8M | 0.01% | −1,646−4.0% | Reduced |
| Reinhart Partners, Inc. | 41,694 | $74.9M | 2.56% | −784−1.8% | Reduced |
| Geode Capital Management, LLC | 42,529 | $76.4M | 0.01% | +343+0.8% | Added |
| State Street Corp | 57,241 | $102.8M | 0.00% | +2,297+4.2% | Added |
| T. Rowe Price Investment Management, Inc. | 62,941 | $113.0M | 0.07% | +475+0.8% | Added |
| London Co of Virginia | 68,770 | $123.5M | 0.70% | −388−0.6% | Reduced |
| Fiduciary Management Inc | 71,478 | $128.4M | 1.23% | −317−0.4% | Reduced |
| Cooke & Bieler LP | 76,781 | $137.9M | 1.38% | +22,129+40.5% | Added |
| Wallace Capital Management Inc. | 79,036 | $141.9M | 19.34% | −895−1.1% | Reduced |
| Neuberger Berman Group LLC | 83,699 | $150.3M | 0.12% | +26,835+47.2% | Added |
| Boston Partners | 89,394 | $160.5M | 0.18% | +4,158+4.9% | Added |
| Fuller & Thaler Asset Management, Inc. | 100,984 | $181.3M | 0.66% | −9,108−8.3% | Reduced |
| River Road Asset Management, LLC | 109,892 | $196.5M | 2.49% | +227+0.2% | Added |
| BlackRock, Inc. | 113,158 | $203.2M | 0.00% | −3,641−3.1% | Reduced |
| Dimensional Fund Advisors LP | 155,753 | $279.7M | 0.06% | −864−0.6% | Reduced |
| Morgan Stanley | 165,064 | $296.4M | 0.02% | −5,567−3.3% | Reduced |
| Vanguard Group Inc | 249,170 | $447.4M | 0.01% | −946−0.4% | Reduced |
| Alaska Permanent Fund Corp | 0 | $0 | 0.00% | −5,902−100.0% | Sold out |
| Dark Forest Capital Management LP | 0 | $0 | 0.00% | −1,491−100.0% | Sold out |
| Schonfeld Strategic Advisors LLC | 0 | $0 | 0.00% | −800−100.0% | Sold out |
| Virginia Retirement Systems Et Al | 0 | $0 | 0.00% | −700−100.0% | Sold out |
| SG Americas Securities, LLC | 0 | $0 | 0.00% | −689−100.0% | Sold out |
| Ofi Invest Asset Management | 0 | $0 | 0.00% | −736−100.0% | Sold out |
| Renaissance Technologies LLC | 0 | $0 | 0.00% | −600−100.0% | Sold out |
| TownSquare Capital, LLC | 0 | $0 | 0.00% | −357−100.0% | Sold out |
| Susquehanna Fundamental Investments, LLC | 0 | $0 | 0.00% | −331−100.0% | Sold out |
| Two Sigma Investments, LP | 0 | $0 | 0.00% | −300−100.0% | Sold out |
| Vestcor Inc | 0 | $0 | 0.00% | −219−100.0% | Sold out |
| Pitcairn Co | 0 | $0 | 0.00% | −133−100.0% | Sold out |
| Principal Financial Group Inc | 0 | $0 | 0.00% | −125−100.0% | Sold out |
| HB Wealth Management, LLC | 0 | $0 | 0.00% | −121−100.0% | Sold out |
| Magnetar Financial LLC | 0 | $0 | 0.00% | −118−100.0% | Sold out |
| Glenview Trust Co | 0 | $0 | 0.00% | −110−100.0% | Sold out |
| Brinker Capital Investments, LLC | 0 | $0 | 0.00% | −108−100.0% | Sold out |
| HBK Sorce Advisory LLC | 0 | $0 | 0.00% | −108−100.0% | Sold out |
| Ballentine Partners, LLC | 0 | $0 | 0.00% | −106−100.0% | Sold out |
| Custom Index Systems, LLC | 0 | $0 | 0.00% | −104−100.0% | Sold out |
| Coldstream Capital Management Inc | 0 | $0 | 0.00% | −94−100.0% | Sold out |
| Stonebridge Financial Group, LLC | 0 | $0 | 0.00% | −60−100.0% | Sold out |
| Quent Capital, LLC | 0 | $0 | 0.00% | −56−100.0% | Sold out |
| Hexagon Capital Partners LLC | 0 | $0 | 0.00% | −17−100.0% | Sold out |
| Corebridge Financial, Inc. | 0 | $0 | 0.00% | −17−100.0% | Sold out |
| Mather Group, LLC. | 0 | $0 | 0.00% | −1−100.0% | Sold out |
| Glenmede Trust Co NA | – | – | – | – | Not filed |
| CAPROCK Group, Inc. | – | – | – | – | Not filed |
| Orion Portfolio Solutions, LLC | – | – | – | – | Not filed |
| Lindbrook Capital, LLC | – | – | – | – | Not filed |