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 |
|---|---|---|---|---|---|
| SHP Wealth Management | 0 | $0 | 0.00% | −1−100.0% | Sold out |
| Bare Financial Services, Inc | 0 | $0 | 0.00% | −1−100.0% | Sold out |
| Boussard & Gavaudan Investment Management LLP | – | – | – | – | Not filed |
| Janus Henderson Group PLC | – | – | – | – | Not filed |
| Skopos Labs, Inc. | – | – | – | – | Not filed |
| Evelyn Partners Asset Management Ltd | – | – | – | – | Not filed |
| CWM, LLC | – | – | – | – | Not filed |