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, Q3 2025
Institutional positions in White Mountains Insurance Group Ltd as of Sep 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
- 338
- +17 vs. Q2 2025
- Shares held
- 2.33M
- +39.1K (+1.7%) vs. Q2 2025
- Total value
- $3.89B
- −$216.4M (−5.3%) vs. Q2 2025
- New holders
- 44
- 105 more added
- Sold out
- 27
- 103 more reduced
4 institutions that held it in Q2 2025 haven't filed for Q3 2025 yet. Not filing isn't selling, so they aren't counted as sold out or in the changes above.
Compare with Q2 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, Q3 2025
Shares, value and share of portfolio for each institution holding White Mountains Insurance Group Ltd; share changes are against Q2 2025.
| Institution | Shares | Value | % of portfolio | Change in shares | Action |
|---|---|---|---|---|---|
| AMG National Trust Bank | 577 | $964.5K | 0.02% | +2+0.3% | Added |
| Chicago Partners Investment Group LLC | 516 | $981.1K | 0.03% | +5+1.0% | Added |
| CI Private Wealth, LLC | 598 | $999.2K | 0.00% | −251−29.6% | Reduced |
| KLP Kapitalforvaltning AS | 605 | $1.01M | 0.00% | +100+19.8% | Added |
| Toroso Investments, LLC | 608 | $1.02M | 0.00% | +608 | New |
| Brandes Investment Partners, LP | 614 | $1.03M | 0.01% | +44+7.7% | Added |
| Nelson, Van Denburg & Campbell Wealth Management Group, LLC | 617 | $1.03M | 0.03% | +617 | New |
| Midwest Professional Planners, LTD. | 622 | $1.04M | 0.25% | −6−1.0% | Reduced |
| Wiley Bros.-Aintree Capital, LLC | 623 | $1.04M | 0.01% | −14−2.2% | Reduced |
| FMR LLC | 625 | $1.04M | 0.00% | +64+11.4% | Added |
| Qube Research & Technologies Ltd | 636 | $1.06M | 0.00% | −1,156−64.5% | Reduced |
| Oak Thistle LLC | 657 | $1.10M | 0.17% | +657 | New |
| Texas Yale Capital Corp. | 680 | $1.14M | 0.04% | +680 | New |
| Park Avenue Securities LLC | 702 | $1.17M | 0.01% | +65+10.2% | Added |
| Captrust Financial Advisors | 707 | $1.18M | 0.00% | −52−6.9% | Reduced |
| Nisa Investment Advisors, LLC | 734 | $1.23M | 0.00% | +3+0.4% | Added |
| Ethic Inc. | 743 | $1.24M | 0.02% | −37−4.7% | Reduced |
| Arizona State Retirement System | 762 | $1.27M | 0.01% | +11+1.5% | Added |
| Aquatic Capital Management LLC | 765 | $1.28M | 0.02% | +765 | New |
| Teachers Retirement System of the State of Kentucky | 767 | $1.28M | 0.01% | −441−36.5% | Reduced |
| Equitable Trust Co | 787 | $1.32M | 0.06% | 00.0% | Unchanged |
| Regions Financial Corp | 792 | $1.32M | 0.01% | +134+20.4% | Added |
| Regency Capital Management Inc. | 811 | $1.36M | 0.64% | +811 | New |
| Public Employees Retirement System of Ohio | 814 | $1.36M | 0.00% | +4+0.5% | Added |
| Sequoia Financial Advisors, LLC | 818 | $1.37M | 0.01% | −12−1.4% | Reduced |
| Summit Trail Advisors, LLC | 828 | $1.38M | 0.02% | +456+122.6% | Added |
| Holocene Advisors, LP | 839 | $1.40M | 0.00% | +839 | New |
| Harbor Capital Advisors, Inc. | 852 | $1.42M | 0.11% | −2,124−71.4% | Reduced |
| Magnetar Financial LLC | 881 | $1.47M | 0.01% | +881 | New |
| Brave Asset Management Inc | 924 | $1.54M | 0.38% | 00.0% | Unchanged |
| Oddo BHF Asset Management SAS | 930 | $1.55M | 0.06% | −34−3.5% | Reduced |
| Millennium Management LLC | 934 | $1.56M | 0.00% | −458−32.9% | Reduced |
| Barclays PLC | 952 | $1.59M | 0.00% | −2,431−71.9% | Reduced |
| Alliancebernstein L.P. | 955 | $1.60M | 0.00% | −172−15.3% | Reduced |
| O'Shaughnessy Asset Management, LLC | 983 | $1.64M | 0.01% | +44+4.7% | Added |
| Autumn Glory Partners, LLC | 1,080 | $1.81M | 0.74% | 00.0% | Unchanged |
| Cove Street Capital, LLC | 1,083 | $1.81M | 2.36% | +609+128.5% | Added |
| Handelsbanken Fonder AB | 1,100 | $1.84M | 0.01% | +500+83.3% | Added |
| Police & Firemen's Retirement System of New Jersey | 1,117 | $1.87M | 0.02% | +183+19.6% | Added |
| Janus Henderson Group PLC | 1,123 | $1.88M | 0.00% | 00.0% | Unchanged |
| Treasurer of the State of North Carolina | 1,125 | $1.88M | 0.01% | −37−3.2% | Reduced |
| State of New Jersey Common Pension Fund D | 1,155 | $1.93M | 0.01% | +107+10.2% | Added |
| TD Asset Management Inc | 1,166 | $1.95M | 0.00% | −452−27.9% | Reduced |
| Pecaut & Co. | 1,167 | $1.95M | 0.63% | 00.0% | Unchanged |
| Truist Financial Corp | 1,173 | $1.96M | 0.00% | −67−5.4% | Reduced |
| Northern Oak Wealth Management Inc | 1,176 | $1.97M | 0.24% | 00.0% | Unchanged |
| Leuthold Group, LLC | 1,206 | $2.02M | 0.22% | +41+3.5% | Added |
| Main Street Financial Solutions, LLC | 1,261 | $2.11M | 0.14% | −32−2.5% | Reduced |
| Stifel Financial Corp | 1,316 | $2.20M | 0.00% | −28−2.1% | Reduced |
| Colony Group, LLC | 1,353 | $2.26M | 0.00% | −243−15.2% | Reduced |
| Edgestream Partners, L.P. | 1,371 | $2.29M | 0.07% | −6,438−82.4% | Reduced |
| HighTower Advisors, LLC | 1,465 | $2.45M | 0.00% | +1+0.1% | Added |
| Citigroup Inc | 1,489 | $2.49M | 0.00% | +127+9.3% | Added |
| BNP Paribas Arbitrage, SA | 1,536 | $2.57M | 0.00% | +1,348+717.0% | Added |
| Oppenheimer Asset Management Inc. | 1,572 | $2.63M | 0.03% | +209+15.3% | Added |
| Atlantic Union Bankshares Corp | 1,765 | $2.95M | 0.06% | +1,765 | New |
| Royal Bank of Canada | 1,770 | $2.96M | 0.00% | −420−19.2% | Reduced |
| Agf Management Ltd | 1,780 | $2.98M | 0.01% | +448+33.6% | Added |
| Renaissance Technologies LLC | 1,851 | $3.09M | 0.00% | +1,851 | New |
| Parsons Capital Management Inc | 1,882 | $3.15M | 0.18% | −10−0.5% | Reduced |
| Price T Rowe Associates Inc | 1,882 | $3.15M | 0.00% | +131+7.5% | Added |
| Cerity Partners LLC | 1,940 | $3.24M | 0.01% | +40+2.1% | Added |
| Forum Financial Management, LP | 2,016 | $3.37M | 0.05% | 00.0% | Unchanged |
| Davenport & Co LLC | 2,173 | $3.63M | 0.02% | 00.0% | Unchanged |
| American Century Companies Inc | 2,242 | $3.75M | 0.00% | −4,123−64.8% | Reduced |
| LPL Financial LLC | 2,306 | $3.85M | 0.00% | +321+16.2% | Added |
| California State Teachers Retirement System | 2,433 | $4.07M | 0.00% | +61+2.6% | Added |
| D. E. Shaw & Co., Inc. | 2,512 | $4.20M | 0.00% | +76+3.1% | Added |
| New York State Common Retirement Fund | 2,519 | $4.21M | 0.01% | 00.0% | Unchanged |
| MML Investors Services, LLC | 2,852 | $4.77M | 0.01% | +118+4.3% | Added |
| Lighthouse Investment Partners, LLC | 2,939 | $4.91M | 0.18% | +2,939 | New |
| Ameriprise Financial Inc | 3,028 | $5.06M | 0.00% | −454−13.0% | Reduced |
| Creative Planning | 3,102 | $5.18M | 0.00% | +260+9.1% | Added |
| State Board of Administration of Florida Retirement System | 3,142 | $5.25M | 0.01% | +529+20.2% | Added |
| Lee Danner & Bass Inc | 3,148 | $5.26M | 0.38% | 00.0% | Unchanged |
| Invesco Ltd. | 3,317 | $5.54M | 0.00% | −329−9.0% | Reduced |
| Brandywine Global Investment Management, LLC | 3,326 | $5.56M | 0.04% | −200−5.7% | Reduced |
| Nuveen, LLC | 3,458 | $5.78M | 0.00% | 00.0% | Unchanged |
| HRT Financial LP | 3,587 | $6.00M | 0.02% | −1,500−29.5% | Reduced |
| Prospector Partners LLC | 3,783 | $6.32M | 0.76% | −293−7.2% | Reduced |
| Legal & General Group Plc | 4,049 | $6.77M | 0.00% | −260−6.0% | Reduced |
| Rhumbline Advisers | 4,232 | $7.07M | 0.01% | −48−1.1% | Reduced |
| JPMorgan Chase & Co | 4,322 | $7.22M | 0.00% | +1,999+86.1% | Added |
| Jane Street Group, LLC | 4,820 | $8.06M | 0.01% | −1,251−20.6% | Reduced |
| Swiss National Bank | 4,946 | $8.27M | 0.00% | 00.0% | Unchanged |
| Williams Jones Wealth Management, LLC. | 5,193 | $8.68M | 0.10% | 00.0% | Unchanged |
| SEI Investments Co | 5,386 | $9.00M | 0.01% | +481+9.8% | Added |
| Phocas Financial Corp. | 5,505 | $9.20M | 1.19% | +113+2.1% | Added |
| Bradley Foster & Sargent Inc | 5,546 | $9.27M | 0.14% | +24+0.4% | Added |
| AQR Capital Management LLC | 5,913 | $9.84M | 0.01% | −2,171−26.9% | Reduced |
| Goldman Sachs Group Inc | 5,911 | $9.88M | 0.00% | −974−14.1% | Reduced |
| Quantinno Capital Management LP | 6,054 | $10.1M | 0.03% | +1,764+41.1% | Added |
| Royce & Associates LP | 6,302 | $10.5M | 0.11% | −301−4.6% | Reduced |
| Gotham Asset Management, LLC | 6,899 | $11.5M | 0.05% | +5,939+618.6% | Added |
| Hotchkis & Wiley Capital Management LLC | 7,106 | $11.9M | 0.04% | +237+3.5% | Added |
| Susquehanna International Group, LLP | 7,360 | $12.3M | 0.02% | +7,072+2,455.6% | Added |
| GW&K Investment Management, LLC | 8,010 | $13.4M | 0.12% | −262−3.2% | Reduced |
| Perpetual Ltd | 8,127 | $13.6M | 0.17% | +400+5.2% | Added |
| Victory Capital Management Inc | 8,526 | $14.3M | 0.01% | −9,114−51.7% | Reduced |
| Thompson Siegel & Walmsley LLC | 8,652 | $14.5M | 0.23% | +347+4.2% | Added |