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 |
|---|---|---|---|---|---|
| Janney Montgomery Scott LLC | 482 | $1.00M | 0.00% | +20+4.3% | Added |
| Prospector Partners LLC | 490 | $1.02M | 2.18% | −3,293−87.0% | Reduced |
| Entropy Technologies, LP | 490 | $1.02M | 0.06% | +490 | New |
| CAPROCK Group, Inc. | 509 | $1.06M | 0.02% | +17+3.5% | Added |
| Chicago Partners Investment Group LLC | 523 | $1.08M | 0.03% | +7+1.4% | Added |
| Edgestream Partners, L.P. | 529 | $1.10M | 0.03% | −842−61.4% | Reduced |
| Oak Thistle LLC | 530 | $1.10M | 0.15% | −127−19.3% | Reduced |
| Qube Research & Technologies Ltd | 532 | $1.11M | 0.00% | −104−16.4% | Reduced |
| B.O.S.S. Retirement Advisors, LLC | 533 | $1.11M | 0.35% | 00.0% | Unchanged |
| The PNC Financial Services Group, Inc. | 536 | $1.11M | 0.00% | +98+22.4% | Added |
| Manufacturers Life Insurance Company, The | 555 | $1.15M | 0.00% | +21+3.9% | Added |
| Barclays PLC | 559 | $1.16M | 0.00% | −393−41.3% | Reduced |
| Jain Global LLC | 559 | $1.16M | 0.01% | +260+87.0% | Added |
| King Luther Capital Management Corp | 560 | $1.16M | 0.00% | 00.0% | Unchanged |
| Sendero Wealth Management, LLC | 562 | $1.17M | 0.13% | 00.0% | Unchanged |
| Farther Finance Advisors, LLC | 570 | $1.18M | 0.01% | +94+19.7% | Added |
| AMG National Trust Bank | 595 | $1.24M | 0.03% | +18+3.1% | Added |
| KLP Kapitalforvaltning AS | 595 | $1.24M | 0.00% | −10−1.7% | Reduced |
| Summit Trail Advisors, LLC | 600 | $1.25M | 0.02% | −228−27.5% | Reduced |
| Nelson, Van Denburg & Campbell Wealth Management Group, LLC | 617 | $1.28M | 0.04% | 00.0% | Unchanged |
| Robeco Institutional Asset Management B.V. | 623 | $1.29M | 0.00% | −16,616−96.4% | Reduced |
| Wiley Bros.-Aintree Capital, LLC | 638 | $1.33M | 0.01% | +15+2.4% | Added |
| Jump Financial, LLC | 658 | $1.37M | 0.02% | +658 | New |
| Brandes Investment Partners, LP | 665 | $1.38M | 0.01% | +51+8.3% | Added |
| Ethic Inc. | 672 | $1.40M | 0.02% | −71−9.6% | Reduced |
| Texas Yale Capital Corp. | 687 | $1.43M | 0.04% | +7+1.0% | Added |
| Captrust Financial Advisors | 705 | $1.47M | 0.00% | −2−0.3% | Reduced |
| Squarepoint Ops LLC | 706 | $1.47M | 0.00% | +528+296.6% | Added |
| Mercer Global Advisors Inc | 715 | $1.49M | 0.00% | +568+386.4% | Added |
| Arizona State Retirement System | 718 | $1.49M | 0.01% | −44−5.8% | Reduced |
| Private Management Group Inc | 726 | $1.51M | 0.04% | +726 | New |
| Nisa Investment Advisors, LLC | 734 | $1.53M | 0.01% | 00.0% | Unchanged |
| Truist Financial Corp | 736 | $1.53M | 0.00% | −437−37.3% | Reduced |
| Park Avenue Securities LLC | 761 | $1.58M | 0.01% | +59+8.4% | Added |
| Teachers Retirement System of the State of Kentucky | 767 | $1.59M | 0.01% | 00.0% | Unchanged |
| Public Employees Retirement System of Ohio | 776 | $1.61M | 0.01% | −38−4.7% | Reduced |
| Regions Financial Corp | 792 | $1.65M | 0.01% | 00.0% | Unchanged |
| Alliancebernstein L.P. | 807 | $1.68M | 0.00% | −148−15.5% | Reduced |
| Arrowstreet Capital, Limited Partnership | 811 | $1.69M | 0.00% | +811 | New |
| Main Street Financial Solutions, LLC | 835 | $1.74M | 0.13% | −426−33.8% | Reduced |
| Equitable Trust Co | 840 | $1.75M | 0.08% | +53+6.7% | Added |
| Millennium Management LLC | 856 | $1.78M | 0.00% | −78−8.4% | Reduced |
| Harbor Capital Advisors, Inc. | 864 | $1.79M | 0.14% | +12+1.4% | Added |
| Handelsbanken Fonder AB | 880 | $1.83M | 0.01% | −220−20.0% | Reduced |
| American Century Companies Inc | 895 | $1.86M | 0.00% | −1,347−60.1% | Reduced |
| Sequoia Financial Advisors, LLC | 906 | $1.88M | 0.01% | +88+10.8% | Added |
| CI Private Wealth, LLC | 906 | $1.88M | 0.00% | +308+51.5% | Added |
| Zurcher Kantonalbank (Zurich Cantonalbank) | 913 | $1.90M | 0.00% | +660+260.9% | Added |
| Brave Asset Management Inc | 924 | $1.92M | 0.45% | 00.0% | Unchanged |
| O'Shaughnessy Asset Management, LLC | 934 | $1.94M | 0.01% | −49−5.0% | Reduced |
| FMR LLC | 939 | $1.95M | 0.00% | +314+50.2% | Added |
| Holocene Advisors, LP | 998 | $2.07M | 0.00% | +159+19.0% | Added |
| TD Asset Management Inc | 1,000 | $2.08M | 0.00% | −166−14.2% | Reduced |
| Treasurer of the State of North Carolina | 1,034 | $2.15M | 0.01% | −91−8.1% | Reduced |
| Police & Firemen's Retirement System of New Jersey | 1,070 | $2.22M | 0.02% | −47−4.2% | Reduced |
| Autumn Glory Partners, LLC | 1,080 | $2.24M | 0.79% | 00.0% | Unchanged |
| Royal Bank of Canada | 1,097 | $2.28M | 0.00% | −673−38.0% | Reduced |
| Marshall Wace, LLP | 1,098 | $2.28M | 0.00% | +1,098 | New |
| Leuthold Group, LLC | 1,117 | $2.32M | 0.25% | −89−7.4% | Reduced |
| Janus Henderson Group PLC | 1,123 | $2.34M | 0.00% | 00.0% | Unchanged |
| State of New Jersey Common Pension Fund D | 1,135 | $2.36M | 0.01% | −20−1.7% | Reduced |
| Pecaut & Co. | 1,167 | $2.43M | 0.78% | 00.0% | Unchanged |
| Northern Oak Wealth Management Inc | 1,176 | $2.44M | 0.31% | 00.0% | Unchanged |
| Aquatic Capital Management LLC | 1,180 | $2.45M | 0.07% | +415+54.2% | Added |
| Citadel Advisors LLC | 1,193 | $2.48M | 0.00% | +912+324.6% | Added |
| Stifel Financial Corp | 1,312 | $2.73M | 0.00% | −4−0.3% | Reduced |
| Agf Management Ltd | 1,408 | $2.93M | 0.01% | −372−20.9% | Reduced |
| HighTower Advisors, LLC | 1,447 | $3.01M | 0.00% | −18−1.2% | Reduced |
| Colony Group, LLC | 1,610 | $3.10M | 0.00% | +257+19.0% | Added |
| Renaissance Technologies LLC | 1,501 | $3.12M | 0.00% | −350−18.9% | Reduced |
| Oppenheimer Asset Management Inc. | 1,502 | $3.12M | 0.04% | −70−4.5% | Reduced |
| Regency Capital Management Inc. | 1,635 | $3.40M | 1.41% | +824+101.6% | Added |
| Jane Street Group, LLC | 1,707 | $3.55M | 0.00% | −3,113−64.6% | Reduced |
| Atlantic Union Bankshares Corp | 1,765 | $3.67M | 0.07% | 00.0% | Unchanged |
| JPMorgan Chase & Co | 1,806 | $3.75M | 0.00% | −2,516−58.2% | Reduced |
| Citigroup Inc | 1,849 | $3.84M | 0.00% | +360+24.2% | Added |
| Parsons Capital Management Inc | 1,872 | $3.89M | 0.21% | −10−0.5% | Reduced |
| LPL Financial LLC | 1,965 | $4.08M | 0.00% | −341−14.8% | Reduced |
| Price T Rowe Associates Inc | 1,990 | $4.14M | 0.00% | +108+5.7% | Added |
| Forum Financial Management, LP | 2,016 | $4.19M | 0.05% | 00.0% | Unchanged |
| Davenport & Co LLC | 2,123 | $4.41M | 0.02% | −50−2.3% | Reduced |
| California State Teachers Retirement System | 2,457 | $5.11M | 0.01% | +24+1.0% | Added |
| New York State Common Retirement Fund | 2,513 | $5.22M | 0.01% | −6−0.2% | Reduced |
| Triad Investment Management | 2,548 | $5.29M | 5.36% | +2,548 | New |
| State Board of Administration of Florida Retirement System | 2,792 | $5.80M | 0.01% | −350−11.1% | Reduced |
| MML Investors Services, LLC | 2,935 | $6.10M | 0.01% | +83+2.9% | Added |
| Invesco Ltd. | 2,995 | $6.22M | 0.00% | −322−9.7% | Reduced |
| Legal & General Group Plc | 3,037 | $6.31M | 0.00% | −1,012−25.0% | Reduced |
| Ameriprise Financial Inc | 3,053 | $6.34M | 0.00% | +25+0.8% | Added |
| Lee Danner & Bass Inc | 3,103 | $6.45M | 0.46% | −45−1.4% | Reduced |
| Brandywine Global Investment Management, LLC | 3,226 | $6.70M | 0.04% | −100−3.0% | Reduced |
| BNP Paribas Arbitrage, SA | 3,340 | $6.94M | 0.00% | +1,804+117.4% | Added |
| Creative Planning | 3,415 | $7.10M | 0.01% | +313+10.1% | Added |
| Nuveen, LLC | 3,475 | $7.22M | 0.00% | +17+0.5% | Added |
| Cerity Partners LLC | 3,543 | $7.36M | 0.01% | +1,603+82.6% | Added |
| Dark Forest Capital Management LP | 3,615 | $7.51M | 0.34% | +3,615 | New |
| Rhumbline Advisers | 4,165 | $8.65M | 0.01% | −67−1.6% | Reduced |
| AQR Capital Management LLC | 4,476 | $9.30M | 0.00% | −1,437−24.3% | Reduced |
| First Trust Advisors LP | 4,555 | $9.47M | 0.01% | +4,555 | New |
| Swiss National Bank | 5,086 | $10.6M | 0.01% | +140+2.8% | Added |