🕵️ White Mountains Insurance Group Ltd ($WTM)
SEC insider & ownership activity, last 12 months · CIK 776867 · every row links its SEC filing
Insider sell value was withheld pending verification over the last 12 months. No red-flag 8-Ks in the window.
Insider flow
0 buyers, $0 (0 lots) · 3 sellers, value withheld pending verification (3 lots)
| Insider | Buys | Bought | Sells | Sold | Last |
|---|---|---|---|---|---|
| Campbell Reid Tarlton | 0 | – | 1 | value withheld pending verification | Dec 19, 2025 |
| Philip A. Gelston | 0 | – | 1 | value withheld pending verification | Dec 16, 2025 |
| Rountree George Manning | 0 | – | 1 | value withheld pending verification | Dec 19, 2025 |
5%+ holders
| Holder | Stake | Class | Schedule | Event | |
|---|---|---|---|---|---|
| Vanguard Capital Management | 5.2% | 13G | Apr 30, 2026 | filing ↗ |
Planned insider sales (Form 144)
No sale notices filed in the last 12 months.
Material events (8-K)
| Item | Event date | |
|---|---|---|
| Officer/director changes (5.02) | Aug 26, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Aug 26, 2026 | filing ↗ |
| Earnings (2.02) | Aug 6, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Aug 6, 2026 | filing ↗ |
| Reg FD disclosure (7.01) | Jun 5, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Jun 5, 2026 | filing ↗ |
| Officer/director changes (5.02) | May 21, 2026 | filing ↗ |
| Shareholder vote (5.07) | May 21, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | May 21, 2026 | filing ↗ |
| Material agreement (1.01) | May 14, 2026 | filing ↗ |
| New financial obligation (2.03) | May 14, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | May 14, 2026 | filing ↗ |
| Earnings (2.02) | May 6, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | May 6, 2026 | filing ↗ |
| Other events (8.01) | Apr 1, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Apr 1, 2026 | filing ↗ |
| Other events (8.01) | Feb 26, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Feb 26, 2026 | filing ↗ |
| Earnings (2.02) | Feb 6, 2026 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Feb 6, 2026 | filing ↗ |
| Other events (8.01) | Jan 7, 2026 | filing ↗ |
| Acquisition or disposition (2.01) | Dec 5, 2025 | filing ↗ |
| Other events (8.01) | Dec 5, 2025 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Dec 5, 2025 | filing ↗ |
| Earnings (2.02) | Nov 6, 2025 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Nov 6, 2025 | filing ↗ |
| Material agreement (1.01) | Oct 2, 2025 | filing ↗ |
| Financial Statements and Exhibits (9.01) | Oct 2, 2025 | filing ↗ |