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 2026
Institutional positions in White Mountains Insurance Group Ltd as of Jun 30, 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
- 356
- −7 vs. Q1 2026
- Shares held
- 2.20M
- +8.83K (+0.4%) vs. Q1 2026
- Total value
- $4.57B
- −$252.8M (−5.2%) vs. Q1 2026
- New holders
- 39
- 96 more added
- Sold out
- 46
- 146 more reduced
5 institutions that held it in Q1 2026 haven't filed for Q2 2026 yet. Not filing isn't selling, so they aren't counted as sold out or in the changes above.
Compare with Q1 2026: 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 2026
Shares, value and share of portfolio for each institution holding White Mountains Insurance Group Ltd; share changes are against Q1 2026.
| Institution | Shares | Value | % of portfolio | Change in shares | Action |
|---|---|---|---|---|---|
| D. E. Shaw & Co., Inc. | 6,618 | $13.7M | 0.01% | −2,292−25.7% | Reduced |
| HRT Financial LP | 6,760 | $14.0M | 0.03% | +4,385+184.6% | Added |
| Royce & Associates LP | 6,781 | $14.1M | 0.11% | +321+5.0% | Added |
| Hotchkis & Wiley Capital Management LLC | 6,788 | $14.1M | 0.04% | +740+12.2% | Added |
| Citadel Advisors LLC | 7,136 | $14.8M | 0.01% | +4,533+174.1% | Added |
| Arrowstreet Capital, Limited Partnership | 7,284 | $15.1M | 0.01% | +5,371+280.8% | Added |
| Thompson Siegel & Walmsley LLC | 7,656 | $15.9M | 0.29% | +447+6.2% | Added |
| GW&K Investment Management, LLC | 7,839 | $16.3M | 0.13% | −87−1.1% | Reduced |
| SEI Investments Co | 8,108 | $16.8M | 0.01% | −2,990−26.9% | Reduced |
| Bank of New York Mellon Corp | 8,412 | $17.4M | 0.00% | −32−0.4% | Reduced |
| Wells Fargo & Company | 8,710 | $18.1M | 0.00% | −72−0.8% | Reduced |
| Speece Thorson Capital Group Inc | 9,215 | $19.1M | 4.08% | −182−1.9% | Reduced |
| Qube Research & Technologies Ltd | 9,673 | $20.1M | 0.02% | +8,657+852.1% | Added |
| First Trust Advisors LP | 10,604 | $22.0M | 0.01% | +7,546+246.8% | Added |
| Victory Capital Management Inc | 10,684 | $22.2M | 0.01% | −461−4.1% | Reduced |
| Boussard & Gavaudan Gestion SAS | 11,679 | $24.5M | 1.24% | +11,679 | New |
| Goldman Sachs Group Inc | 12,151 | $25.2M | 0.00% | −3,632−23.0% | Reduced |
| Horizon Kinetics Asset Management LLC | 12,206 | $25.3M | 0.29% | −906−6.9% | Reduced |
| Elkhorn Partners Limited Partnership | 12,320 | $25.5M | 21.89% | −380−3.0% | Reduced |
| Quantinno Capital Management LP | 12,624 | $26.2M | 0.03% | +2,840+29.0% | Added |
| Envestnet Asset Management Inc | 13,838 | $28.7M | 0.01% | −1,725−11.1% | Reduced |
| Wellington Management Group LLP | 14,532 | $30.1M | 0.01% | −352−2.4% | Reduced |
| Northern Trust Corp | 14,571 | $30.2M | 0.00% | −924−6.0% | Reduced |
| Raymond James Financial Inc | 14,833 | $30.8M | 0.01% | −9,118−38.1% | Reduced |
| Vanguard Fiduciary Trust Co | 15,319 | $31.8M | 0.01% | +133+0.9% | Added |
| UBS Group AG | 16,198 | $33.6M | 0.01% | +5,757+55.1% | Added |
| Southeastern Asset Management IncSuperinvestorSoutheastern Asset Management (Longleaf) | 17,104 | $35.5M | 1.85% | −1,760−9.3% | Reduced |
| Jane Street Group, LLC | 17,226 | $35.7M | 0.02% | +3,418+24.8% | Added |
| Brown Advisory Inc | 17,722 | $36.7M | 0.06% | −122−0.7% | Reduced |
| Gotham Asset Management, LLC | 17,940 | $37.2M | 0.09% | +8,893+98.3% | Added |
| Allspring Global Investments Holdings, LLC | 18,116 | $37.4M | 0.06% | −496−2.7% | Reduced |
| Mraz, Amerine & Associates, Inc. | 22,218 | $46.1M | 6.61% | +39+0.2% | Added |
| Charles Schwab Investment Management Inc | 23,505 | $48.7M | 0.01% | −736−3.0% | Reduced |
| Bank of America Corp | 25,028 | $51.9M | 0.00% | −3,330−11.7% | Reduced |
| Spears Abacus Advisors LLC | 27,577 | $57.2M | 1.02% | −450−1.6% | Reduced |
| Norges Bank | 27,956 | $58.0M | 0.01% | +27,956 | New |
| American Century Companies Inc | 31,108 | $64.5M | 0.03% | +22,800+274.4% | Added |
| Lord, Abbett & Co. LLC | 32,829 | $68.1M | 0.19% | −281−0.8% | Reduced |
| T. Rowe Price Investment Management, Inc. | 34,237 | $71.0M | 0.05% | −7,276−17.5% | Reduced |
| Reinhart Partners, Inc. | 44,480 | $92.3M | 2.11% | +7,106+19.0% | Added |
| Morgan Stanley | 46,866 | $97.2M | 0.01% | −12,429−21.0% | Reduced |
| Geode Capital Management, LLC | 49,412 | $102.5M | 0.01% | +7,293+17.3% | Added |
| State Street Corp | 50,257 | $104.2M | 0.00% | +1,099+2.2% | Added |
| London Co of Virginia | 54,025 | $112.1M | 0.64% | −3,106−5.4% | Reduced |
| Boston Partners | 55,569 | $115.3M | 0.10% | −1,890−3.3% | Reduced |
| Gendell Jeffrey L | 59,243 | $122.8M | 1.11% | +21,429+56.7% | Added |
| Fiduciary Management Inc | 66,550 | $138.0M | 1.96% | −18,516−21.8% | Reduced |
| Wallace Capital Management Inc. | 80,067 | $166.0M | 18.20% | +1,272+1.6% | Added |
| Cooke & Bieler LP | 85,120 | $176.5M | 2.04% | −19,737−18.8% | Reduced |
| Fuller & Thaler Asset Management, Inc. | 101,892 | $211.3M | 0.58% | −2,669−2.6% | Reduced |
| Vanguard Capital Management LLC | 107,479 | $222.8M | 0.00% | −1,678−1.5% | Reduced |
| Vanguard Portfolio Management LLC | 111,969 | $232.2M | 0.01% | −3,584−3.1% | Reduced |
| River Road Asset Management, LLC | 115,880 | $240.3M | 2.67% | −4,639−3.8% | Reduced |
| BlackRock, Inc. | 117,871 | $244.4M | 0.00% | +4,543+4.0% | Added |
| Neuberger Berman Group LLC | 119,141 | $247.0M | 0.16% | −5,574−4.5% | Reduced |
| Dimensional Fund Advisors LP | 158,954 | $329.6M | 0.06% | +2,336+1.5% | Added |
| Susquehanna International Group, LLP | 0 | $0 | 0.00% | −10,965−100.0% | Sold out |
| Select Equity Group, L.P. | 0 | $0 | 0.00% | −10,560−100.0% | Sold out |
| Marshall Wace, LLP | 0 | $0 | 0.00% | −3,878−100.0% | Sold out |
| Renaissance Technologies LLC | 0 | $0 | 0.00% | −2,611−100.0% | Sold out |
| Dark Forest Capital Management LP | 0 | $0 | 0.00% | −2,255−100.0% | Sold out |
| Diversified Management Inc | 0 | $0 | 0.00% | −1,158−100.0% | Sold out |
| Capula Management Ltd | 0 | $0 | 0.00% | −921−100.0% | Sold out |
| Fieldview Capital Management, LLC | 0 | $0 | 0.00% | −729−100.0% | Sold out |
| Mariner, LLC | 0 | $0 | 0.00% | −607−100.0% | Sold out |
| AMG National Trust Bank | 0 | $0 | 0.00% | −571−100.0% | Sold out |
| Entropy Technologies, LP | 0 | $0 | 0.00% | −470−100.0% | Sold out |
| Main Street Financial Solutions, LLC | 0 | $0 | 0.00% | −439−100.0% | Sold out |
| Bridgewater Associates, LP | 0 | $0 | 0.00% | −414−100.0% | Sold out |
| Natixis | 0 | $0 | 0.00% | −356−100.0% | Sold out |
| CAPROCK Group, Inc. | 0 | $0 | 0.00% | −340−100.0% | Sold out |
| Private Advisor Group, LLC | 0 | $0 | 0.00% | −213−100.0% | Sold out |
| Evercore Wealth Management, LLC | 0 | $0 | 0.00% | −200−100.0% | Sold out |
| Brown Brothers Harriman & Co | 0 | $0 | 0.00% | −199−100.0% | Sold out |
| Ieq Capital, LLC | 0 | $0 | 0.00% | −198−100.0% | Sold out |
| State of Wyoming | 0 | $0 | 0.00% | −179−100.0% | Sold out |
| United Capital Financial Advisers, LLC | 0 | $0 | 0.00% | −166−100.0% | Sold out |
| Keybank National Association | 0 | $0 | 0.00% | −161−100.0% | Sold out |
| Zacks Investment Management | 0 | $0 | 0.00% | −157−100.0% | Sold out |
| Change Path, LLC | 0 | $0 | 0.00% | −150−100.0% | Sold out |
| Chapman Investment Management, LLC | 0 | $0 | 0.00% | −143−100.0% | Sold out |
| CIBC Asset Management Inc | 0 | $0 | 0.00% | −124−100.0% | Sold out |
| Weiss Asset Management LP | 0 | $0 | 0.00% | −120−100.0% | Sold out |
| Catalyst Funds Management Pty Ltd | 0 | $0 | 0.00% | −110−100.0% | Sold out |
| Sagespring Wealth Partners, LLC | 0 | $0 | 0.00% | −101−100.0% | Sold out |
| Buckingham Strategic Partners | 0 | $0 | 0.00% | −99−100.0% | Sold out |
| Connecticut Capital Management Group, LLC | 0 | $0 | 0.00% | −94−100.0% | Sold out |
| MAI Capital Management | 0 | $0 | 0.00% | −81−100.0% | Sold out |
| Anchor Investment Management, LLC | 0 | $0 | 0.00% | −50−100.0% | Sold out |
| Advisory Services Network, LLC | 0 | $0 | 0.00% | −37−100.0% | Sold out |
| Opal Wealth Advisors, LLC | 0 | $0 | 0.00% | −20−100.0% | Sold out |
| CX Institutional | 0 | $0 | 0.00% | −19−100.0% | Sold out |
| Ancora Advisors, LLC | 0 | $0 | 0.00% | −16−100.0% | Sold out |
| Global Assets Advisory, LLC | 0 | $0 | 0.00% | −15−100.0% | Sold out |
| Hillsdale Investment Management Inc. | 0 | $0 | 0.00% | −8−100.0% | Sold out |
| Root Financial Partners, LLC | 0 | $0 | 0.00% | −4−100.0% | Sold out |
| Parkside Financial Bank & Trust | 0 | $0 | 0.00% | −3−100.0% | Sold out |
| Crewe Advisors LLC | 0 | $0 | 0.00% | −3−100.0% | Sold out |
| Twin Peaks Wealth Advisors, LLC | 0 | $0 | 0.00% | −3−100.0% | Sold out |
| First Horizon Corp | 0 | $0 | 0.00% | −1−100.0% | Sold out |