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 |
|---|---|---|---|---|---|
| Venturi Wealth Management, LLC | 243 | $533.9K | 0.02% | +22+10.0% | Added |
| Shotwell Rutter Baer Inc | 242 | $531.7K | 0.31% | 00.0% | Unchanged |
| Voya Investment Management LLC | 237 | $520.7K | 0.00% | −6−2.5% | Reduced |
| Wedbush Securities Inc | 228 | $501.0K | 0.01% | −1−0.4% | Reduced |
| OneAscent Financial Services LLC | 228 | $500.9K | 0.03% | +228 | New |
| Atria Investments LLC | 226 | $496.6K | 0.01% | +17+8.1% | Added |
| Athena Investment Management | 224 | $492.1K | 0.26% | −5−2.2% | Reduced |
| Vestmark Advisory Solutions, Inc. | 223 | $489.9K | 0.01% | −98−30.5% | Reduced |
| Nicolet Bankshares Inc | 223 | $485.8K | 0.02% | +223 | New |
| Principal Securities, Inc. | 215 | $472.3K | 0.01% | −1−0.5% | Reduced |
| Private Advisor Group, LLC | 213 | $468.0K | 0.00% | 00.0% | Unchanged |
| We Are One Seven, LLC | 208 | $457.0K | 0.01% | +4+2.0% | Added |
| Hudson Value Partners, LLC | 206 | $452.6K | 0.14% | 00.0% | Unchanged |
| Sagewood Asset Management LP | 204 | $448.2K | 0.14% | +204 | New |
| Evergreen Capital Management LLC | 202 | $443.8K | 0.01% | +59+41.3% | Added |
| GAMMA Investing LLC | 202 | $443.8K | 0.02% | +3+1.5% | Added |
| SG Americas Securities, LLC | 201 | $442.0K | 0.00% | +135+204.5% | Added |
| Ensign Peak Advisors, Inc | 200 | $439.4K | 0.00% | 00.0% | Unchanged |
| Evercore Wealth Management, LLC | 200 | $439.4K | 0.01% | 00.0% | Unchanged |
| Sage Investment Counsel LLC | 200 | $439.4K | 0.49% | 00.0% | Unchanged |
| Savant Capital, LLC | 199 | $437.2K | 0.00% | +19+10.6% | Added |
| Folger Nolan Fleming Douglas Capital Management, Inc | 199 | $437.2K | 0.04% | 00.0% | Unchanged |
| Brown Brothers Harriman & Co | 199 | $437.2K | 0.00% | +180+947.4% | Added |
| Ieq Capital, LLC | 198 | $435.0K | 0.00% | +198 | New |
| Ritholtz Wealth Management | 196 | $430.6K | 0.01% | +1+0.5% | Added |
| GWM Advisors LLC | 191 | $419.6K | 0.00% | −5−2.6% | Reduced |
| Bryn Mawr Trust Co | 187 | $410.8K | 0.01% | −22−10.5% | Reduced |
| Riverwater Partners LLC | 184 | $404.2K | 0.13% | −6−3.2% | Reduced |
| Xponance, Inc. | 182 | $399.8K | 0.00% | +59+48.0% | Added |
| State of Wyoming | 179 | $393.3K | 0.05% | +45+33.6% | Added |
| Bank of Nova Scotia | 178 | $391.1K | 0.00% | −11−5.8% | Reduced |
| Frank, Rimerman Advisors LLC | 178 | $391.1K | 0.03% | 00.0% | Unchanged |
| Wealth Enhancement Advisory Services, LLC | 176 | $381.9K | 0.00% | −51−22.5% | Reduced |
| M&T Bank Corp | 170 | $373.5K | 0.00% | +4+2.4% | Added |
| Teacher Retirement System of Texas | 169 | $371.3K | 0.00% | +169 | New |
| United Capital Financial Advisers, LLC | 166 | $364.7K | 0.00% | +166 | New |
| Syon Capital LLC | 164 | $360.3K | 0.02% | +24+17.1% | Added |
| Keybank National Association | 161 | $353.7K | 0.00% | −15−8.5% | Reduced |
| Zacks Investment Management | 157 | $344.9K | 0.00% | 00.0% | Unchanged |
| Evelyn Partners Asset Management Ltd | 154 | $338.3K | 0.08% | 00.0% | Unchanged |
| Connable Office Inc | 152 | $333.9K | 0.03% | 00.0% | Unchanged |
| HB Wealth Management, LLC | 151 | $331.7K | 0.00% | +21+16.2% | Added |
| Moneta Group Investment Advisors LLC | 150 | $329.5K | 0.00% | 00.0% | Unchanged |
| Change Path, LLC | 150 | $329.5K | 0.01% | 00.0% | Unchanged |
| Douglass Winthrop Advisors, LLC | 150 | $329.5K | 0.01% | 00.0% | Unchanged |
| TCG Advisory Services, LLC | 150 | $329.5K | 0.01% | +4+2.7% | Added |
| Chapman Investment Management, LLC | 143 | $314.2K | 0.26% | 00.0% | Unchanged |
| US Bancorp | 137 | $301.0K | 0.00% | +13+10.5% | Added |
| Utah Retirement Systems | 134 | $294.4K | 0.00% | 00.0% | Unchanged |
| Amalgamated Bank | 132 | $290.0K | 0.00% | +5+3.9% | Added |
| Quadrant Capital Group LLC | 129 | $283.4K | 0.01% | +1+0.8% | Added |
| Pinnacle Associates Ltd | 128 | $281.2K | 0.00% | +1+0.8% | Added |
| Merit Financial Group, LLC | 125 | $274.7K | 0.00% | +4+3.3% | Added |
| Columbia Asset Management | 125 | $274.6K | 0.05% | 00.0% | Unchanged |
| Kera Capital Partners, Inc. | 125 | $274.6K | 0.03% | +11+9.6% | Added |
| Hengehold Capital Management LLC | 124 | $272.5K | 0.02% | −103−45.4% | Reduced |
| CIBC Asset Management Inc | 124 | $272.4K | 0.00% | 00.0% | Unchanged |
| Storgate, LLC | 124 | $272.4K | 0.21% | +11+9.7% | Added |
| Kestra Advisory Services, LLC | 122 | $268.2K | 0.00% | −49−28.7% | Reduced |
| Weiss Asset Management LP | 120 | $263.6K | 0.00% | +120 | New |
| State of Alaska, Department of Revenue | 119 | $261.0K | 0.00% | 00.0% | Unchanged |
| First Manhattan Co | 115 | $252.7K | 0.00% | +15+15.0% | Added |
| One Wealth Advisors, LLC | 111 | $243.9K | 0.03% | 00.0% | Unchanged |
| Great Lakes Advisors, LLC | 110 | $241.7K | 0.00% | 00.0% | Unchanged |
| Catalyst Funds Management Pty Ltd | 110 | $241.7K | 0.04% | +110 | New |
| NewEdge Wealth, LLC | 105 | $230.7K | 0.00% | −17−13.9% | Reduced |
| DnB Asset Management AS | 105 | $230.7K | 0.00% | +105 | New |
| Eagle Bay Advisors LLC | 104 | $228.5K | 0.20% | +13+14.3% | Added |
| Perigon Wealth Management, LLC | 102 | $224.1K | 0.00% | 00.0% | Unchanged |
| Ballentine Partners, LLC | 101 | $221.9K | 0.00% | −4−3.8% | Reduced |
| Gladstone Institutional Advisory LLC | 101 | $221.9K | 0.01% | +1+1.0% | Added |
| Sagespring Wealth Partners, LLC | 101 | $221.2K | 0.00% | −4−3.8% | Reduced |
| Citadel Investment Advisory, Inc. | 100 | $220.0K | 0.11% | 00.0% | Unchanged |
| Baldwin Brothers Inc | 100 | $219.7K | 0.02% | 00.0% | Unchanged |
| Eastern Bank | 100 | $219.7K | 0.00% | 00.0% | Unchanged |
| Clearbridge Investments, LLC | 100 | $219.7K | 0.00% | 00.0% | Unchanged |
| Chicago Trust Co NA | 100 | $219.7K | 0.04% | 00.0% | Unchanged |
| Ackerman Asset Management, LLC | 100 | $219.7K | 0.15% | 00.0% | Unchanged |
| Equity Investment Corp | 99 | $217.5K | 0.00% | −14−12.4% | Reduced |
| Buckingham Strategic Partners | 99 | $217.5K | 0.00% | +99 | New |
| Custom Index Systems, LLC | 96 | $210.9K | 0.09% | +96 | New |
| Vise Technologies, Inc. | 100 | $207.8K | 0.00% | 00.0% | Unchanged |
| Connecticut Capital Management Group, LLC | 94 | $206.5K | 0.20% | +94 | New |
| HSBC Holdings PLC | 94 | $206.5K | 0.00% | +94 | New |
| CWM, LLC | 92 | $202.1K | 0.00% | +74+411.1% | Added |
| Sterling Capital Management LLC | 83 | $182.3K | 0.00% | −63−43.2% | Reduced |
| MAI Capital Management | 81 | $178.0K | 0.00% | +22+37.3% | Added |
| Ronald Blue Trust, Inc. | 77 | $169.2K | 0.00% | −12−13.5% | Reduced |
| Signaturefd, LLC | 75 | $164.8K | 0.00% | +19+33.9% | Added |
| KBC Group NV | 72 | $158.0K | 0.00% | 00.0% | Unchanged |
| Federation des caisses Desjardins du Quebec | 65 | $142.8K | 0.00% | +10+18.2% | Added |
| Smithfield Trust Co | 64 | $141.0K | 0.01% | 00.0% | Unchanged |
| Colonial Trust Co | 61 | $134.0K | 0.02% | 00.0% | Unchanged |
| STRS Ohio | 59 | $129.6K | 0.00% | 00.0% | Unchanged |
| Steward Partners Investment Advisory, LLC | 55 | $120.8K | 0.00% | +5+10.0% | Added |
| Parallel Advisors, LLC | 53 | $116.4K | 0.00% | +4+8.2% | Added |
| Allworth Financial LP | 53 | $116.4K | 0.00% | +10+23.3% | Added |
| Anchor Investment Management, LLC | 50 | $109.8K | 0.01% | 00.0% | Unchanged |
| Stephenson National Bank & Trust | 49 | $107.7K | 0.03% | 00.0% | Unchanged |
| Versant Capital Management, Inc | 49 | $107.7K | 0.01% | +32+188.2% | Added |