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 |
|---|---|---|---|---|---|
| Mariner, LLC | 214 | $357.4K | 0.00% | −528−71.2% | Reduced |
| Private Advisor Group, LLC | 211 | $352.7K | 0.00% | 00.0% | Unchanged |
| Principal Securities, Inc. | 210 | $351.0K | 0.01% | +10+5.0% | Added |
| Bryn Mawr Trust Co | 209 | $349.3K | 0.01% | +69+49.3% | Added |
| Ritholtz Wealth Management | 208 | $347.7K | 0.01% | −6−2.8% | Reduced |
| Voya Investment Management LLC | 208 | $347.7K | 0.00% | −71−25.4% | Reduced |
| National Wealth Management Group, LLC | 208 | $347.7K | 0.13% | +208 | New |
| Hudson Value Partners, LLC | 206 | $344.3K | 0.11% | 00.0% | Unchanged |
| Bank of Nova Scotia | 202 | $337.6K | 0.00% | +6+3.1% | Added |
| SummitTX Capital, L.P. | 200 | $334.3K | 0.01% | −99−33.1% | Reduced |
| Evercore Wealth Management, LLC | 200 | $334.3K | 0.00% | 00.0% | Unchanged |
| Sage Investment Counsel LLC | 200 | $334.3K | 0.37% | 00.0% | Unchanged |
| Neville Rodie & Shaw Inc | 200 | $334.0K | 0.02% | 00.0% | Unchanged |
| Folger Nolan Fleming Douglas Capital Management, Inc | 199 | $332.6K | 0.03% | 00.0% | Unchanged |
| Two Sigma Securities, LLC | 194 | $324.3K | 0.05% | +24+14.1% | Added |
| SG Americas Securities, LLC | 191 | $319.0K | 0.00% | +191 | New |
| Vise Technologies, Inc. | 190 | $317.6K | 0.01% | −6−3.1% | Reduced |
| Riverwater Partners LLC | 190 | $317.6K | 0.13% | +48+33.8% | Added |
| Atria Investments LLC | 187 | $312.7K | 0.00% | −82−30.5% | Reduced |
| We Are One Seven, LLC | 187 | $312.6K | 0.01% | +12+6.9% | Added |
| Susquehanna Portfolio Strategies, LLC | 187 | $312.6K | 0.00% | +187 | New |
| Inceptionr LLC | 185 | $309.2K | 0.07% | +185 | New |
| Savant Capital, LLC | 183 | $305.9K | 0.00% | −4−2.1% | Reduced |
| One Wealth Advisors, LLC | 183 | $305.9K | 0.04% | −32−14.9% | Reduced |
| GAMMA Investing LLC | 183 | $305.9K | 0.02% | +1+0.5% | Added |
| Squarepoint Ops LLC | 178 | $297.5K | 0.00% | −101−36.2% | Reduced |
| Frank, Rimerman Advisors LLC | 177 | $295.9K | 0.02% | 00.0% | Unchanged |
| GWM Advisors LLC | 170 | $284.2K | 0.00% | 00.0% | Unchanged |
| Keybank National Association | 167 | $279.1K | 0.00% | +9+5.7% | Added |
| Marex Group plc | 163 | $272.5K | 0.00% | +163 | New |
| TCG Advisory Services, LLC | 160 | $267.4K | 0.01% | +160 | New |
| Zacks Investment Management | 157 | $262.4K | 0.00% | +9+6.1% | Added |
| Mount Yale Investment Advisors, LLC | 157 | $262.4K | 0.02% | +81+106.6% | Added |
| Vestmark Advisory Solutions, Inc. | 157 | $262.4K | 0.01% | +157 | New |
| Prudential Financial Inc | 156 | $260.8K | 0.00% | +6+4.0% | Added |
| Sterling Capital Management LLC | 154 | $257.4K | 0.00% | −13−7.8% | Reduced |
| Evelyn Partners Asset Management Ltd | 154 | $257.4K | 0.06% | 00.0% | Unchanged |
| Douglass Winthrop Advisors, LLC | 150 | $250.7K | 0.00% | −5−3.2% | Reduced |
| Moneta Group Investment Advisors LLC | 150 | $250.7K | 0.00% | 00.0% | Unchanged |
| Change Path, LLC | 150 | $250.7K | 0.01% | +2+1.4% | Added |
| Kestra Advisory Services, LLC | 149 | $249.8K | 0.00% | +21+16.4% | Added |
| Mercer Global Advisors Inc | 147 | $245.7K | 0.00% | +29+24.6% | Added |
| Evergreen Capital Management LLC | 146 | $244.0K | 0.01% | +31+27.0% | Added |
| Freestone Grove Partners LP | 144 | $240.7K | 0.00% | +144 | New |
| Chapman Investment Management, LLC | 143 | $239.0K | 0.17% | 00.0% | Unchanged |
| Utah Retirement Systems | 134 | $224.0K | 0.00% | 00.0% | Unchanged |
| Quadrant Capital Group LLC | 133 | $222.3K | 0.01% | 00.0% | Unchanged |
| NewEdge Wealth, LLC | 117 | $222.0K | 0.00% | +117 | New |
| Sagespring Wealth Partners, LLC | 132 | $220.7K | 0.00% | −1−0.8% | Reduced |
| Connable Office Inc | 129 | $215.6K | 0.02% | 00.0% | Unchanged |
| Requisite Capital Management, LLC | 129 | $215.6K | 0.04% | +129 | New |
| Pinnacle Associates Ltd | 127 | $212.3K | 0.00% | 00.0% | Unchanged |
| HB Wealth Management, LLC | 126 | $210.6K | 0.00% | +126 | New |
| Amalgamated Bank | 125 | $209.0K | 0.00% | −5−3.8% | Reduced |
| Columbia Asset Management | 125 | $208.9K | 0.04% | 00.0% | Unchanged |
| US Bancorp | 123 | $205.6K | 0.00% | +8+7.0% | Added |
| Merit Financial Group, LLC | 120 | $200.6K | 0.00% | −2−1.6% | Reduced |
| Xponance, Inc. | 120 | $200.6K | 0.00% | 00.0% | Unchanged |
| Roehl & Yi Investment Advisors, LLC | 120 | $200.6K | 0.09% | 00.0% | Unchanged |
| State of Alaska, Department of Revenue | 117 | $195.0K | 0.00% | +117 | New |
| Ronald Blue Trust, Inc. | 113 | $188.9K | 0.00% | +36+46.8% | Added |
| Macquarie Group Ltd | 107 | $178.9K | 0.00% | +107 | New |
| Eastern Bank | 100 | $167.2K | 0.00% | 00.0% | Unchanged |
| Citadel Investment Advisory, Inc. | 100 | $167.0K | 0.08% | 00.0% | Unchanged |
| Bessemer Group Inc | 94 | $157.0K | 0.00% | 00.0% | Unchanged |
| LRI Investments, LLC | 82 | $137.4K | 0.01% | −8−8.9% | Reduced |
| State of Wyoming | 76 | $127.0K | 0.01% | 00.0% | Unchanged |
| KBC Group NV | 72 | $120.0K | 0.00% | 00.0% | Unchanged |
| Parkside Financial Bank & Trust | 68 | $113.7K | 0.01% | −3−4.2% | Reduced |
| Smithfield Trust Co | 64 | $107.0K | 0.00% | 00.0% | Unchanged |
| MAI Capital Management | 62 | $103.6K | 0.00% | −1−1.6% | Reduced |
| Colonial Trust Co | 61 | $102.0K | 0.01% | 00.0% | Unchanged |
| STRS Ohio | 60 | $100.3K | 0.00% | −1,515−96.2% | Reduced |
| Quent Capital, LLC | 60 | $100.3K | 0.01% | +60 | New |
| Signaturefd, LLC | 53 | $88.6K | 0.00% | +1+1.9% | Added |
| Anchor Investment Management, LLC | 50 | $83.6K | 0.01% | 00.0% | Unchanged |
| Federation des caisses Desjardins du Quebec | 50 | $83.6K | 0.00% | 00.0% | Unchanged |
| Steward Partners Investment Advisory, LLC | 47 | $78.6K | 0.00% | −58−55.2% | Reduced |
| Parallel Advisors, LLC | 45 | $75.2K | 0.00% | −1−2.2% | Reduced |
| Advisory Services Network, LLC | 45 | $75.2K | 0.00% | +45 | New |
| MetLife Investment Management | 42 | $70.2K | 0.00% | 00.0% | Unchanged |
| Valley National Advisers Inc | 40 | $66.0K | 0.01% | 00.0% | Unchanged |
| Allworth Financial LP | 35 | $58.5K | 0.00% | +7+25.0% | Added |
| WPG Advisers, LLC | 32 | $53.5K | 0.04% | 00.0% | Unchanged |
| Clearstead Advisors, LLC | 31 | $51.8K | 0.00% | −23−42.6% | Reduced |
| Quarry LP | 31 | $51.8K | 0.01% | +31 | New |
| EverSource Wealth Advisors, LLC | 30 | $50.1K | 0.00% | −13−30.2% | Reduced |
| Stephenson National Bank & Trust | 29 | $48.5K | 0.01% | +3+11.5% | Added |
| Covestor Ltd | 28 | $48.0K | 0.03% | +22+366.7% | Added |
| CIBC Private Wealth Group, LLC | 25 | $41.8K | 0.00% | 00.0% | Unchanged |
| Fortitude Family Office, LLC | 21 | $35.1K | 0.01% | 00.0% | Unchanged |
| Ameriflex Group, Inc. | 20 | $33.4K | 0.01% | +20 | New |
| Delta Asset Management LLC | 19 | $31.8K | 0.00% | 00.0% | Unchanged |
| TD Private Client Wealth LLC | 18 | $30.1K | 0.00% | −14−43.8% | Reduced |
| Fifth Third Bancorp | 17 | $28.4K | 0.00% | 00.0% | Unchanged |
| Huntington National Bank | 16 | $26.7K | 0.00% | 00.0% | Unchanged |
| Versant Capital Management, Inc | 16 | $26.7K | 0.00% | −17−51.5% | Reduced |
| Gables Capital Management Inc. | 15 | $25.1K | 0.01% | 00.0% | Unchanged |
| Private Trust Co NA | 15 | $25.1K | 0.00% | +1+7.1% | Added |
| CWM, LLC | 15 | $25.0K | 0.00% | −16−51.6% | Reduced |