WHITE MOUNTAINS INSURANCE GROUP LTD — Insider Transactions
Form 4 filings by directors, officers, and 10%+ shareholders
SEC rules require corporate insiders — including directors, executive officers, and any shareholder owning more than 10% of a company's shares — to report changes in their ownership within two business days of a transaction. These disclosures are filed as Form 4. Open-market purchases (code P) are generally considered the most meaningful signal, as insiders are spending their own money.
| Insider | Title | Type | Shares | Price | Value | Owns After | Date |
|---|---|---|---|---|---|---|---|
| Hildreth Michaela | MD & Chief Accounting Officer | Gift | 60 | — | — | 2,165 | Dec 23, 2025 |
| CAMPBELL REID TARLTON | — | Sale | 5,000 | $2,050.00 | $10,250,000 | 10,440 | Dec 19, 2025 |
| CAMPBELL REID TARLTON | — | Sale | 5,000 | — | — | 10,440 | Dec 19, 2025 |
| Rountree George Manning | Chief Executive Officer | Sale | 5,000 | $2,050.00 | $10,250,000 | 13,809 | Dec 19, 2025 |
| Gelston Philip A | — | Sale | 165 | $2,048.51 | $338,004 | 1,568 | Dec 16, 2025 |
| CAMPBELL REID TARLTON | — | Gift | 50 | — | — | 15,440 | Nov 25, 2025 |
| Tanner David Allen | — | Gift | 4 | — | — | 2,104 | Nov 10, 2025 |
| SHANK SUZANNE F. | — | Award / Grant | 150 | — | — | 871 | May 22, 2025 |
| Yi Steven | — | Award / Grant | 150 | — | — | 525 | May 22, 2025 |
| Tanner David Allen | — | Award / Grant | 150 | — | — | 2,108 | May 22, 2025 |
| Hicks Weston M | — | Award / Grant | 210 | — | — | 2,746 | May 22, 2025 |
| Gelston Philip A | — | Award / Grant | 150 | — | — | 1,733 | May 22, 2025 |
| Dillon Margaret | — | Award / Grant | 150 | — | — | 945 | May 22, 2025 |
| CHOKSI MARY C | — | Award / Grant | 150 | — | — | 1,858 | May 22, 2025 |
| Carlson Peter M | — | Award / Grant | 150 | — | — | 717 | May 22, 2025 |
| CAMPBELL REID TARLTON | — | Award / Grant | 150 | — | — | 15,490 | May 22, 2025 |
| Rountree George Manning | Chief Executive Officer | Award / Grant | 1,625 | — | — | 5,425 | Feb 26, 2025 |
| Caffrey Liam P | EVP& Chief Financial Officer | Award / Grant | 1,025 | — | — | 3,400 | Feb 26, 2025 |
| Harrison Giles E | EVP & Chief Strategy Officer | Award / Grant | 900 | — | — | 1,900 | Feb 26, 2025 |
| SEELIG ROBERT LAWRENCE | EVP & General Counsel | Award / Grant | 825 | — | — | 2,725 | Feb 26, 2025 |
| Hildreth Michaela | MD & Chief Accounting Officer | Award / Grant | 625 | — | — | 1,825 | Feb 26, 2025 |
| Rountree George Manning | Chief Executive Officer | Tax Withholding | 1,067 | $1,945.06 | $2,075,379 | 18,809 | Jan 1, 2025 |
| Caffrey Liam P | President & CFO | Tax Withholding | 420 | $1,945.06 | $816,925 | 830 | Jan 1, 2025 |
| SEELIG ROBERT LAWRENCE | EVP & General Counsel | Tax Withholding | 496 | $1,945.06 | $964,750 | 17,305 | Jan 1, 2025 |
| Hildreth Michaela | MD & Chief Accounting Officer | Tax Withholding | 323 | $1,945.06 | $628,254 | 2,225 | Jan 1, 2025 |
| Hildreth Michaela | MD & Chief Accounting Officer | Gift | 75 | — | — | 1,798 | Nov 29, 2024 |
| Harrison Giles E | EVP & Chief Strategy Officer | Award / Grant | 1,000 | — | — | 1,000 | Jun 10, 2024 |
| Yi Steven | — | Award / Grant | 165 | — | — | 375 | May 23, 2024 |
| Tanner David Allen | — | Award / Grant | 165 | — | — | 1,958 | May 23, 2024 |
| SHANK SUZANNE F. | — | Award / Grant | 165 | — | — | 721 | May 23, 2024 |
| Gelston Philip A | — | Award / Grant | 165 | — | — | 1,583 | May 23, 2024 |
| Dillon Margaret | — | Award / Grant | 165 | — | — | 795 | May 23, 2024 |
| CHOKSI MARY C | — | Award / Grant | 165 | — | — | 1,708 | May 23, 2024 |
| Carlson Peter M | — | Award / Grant | 165 | — | — | 1,133 | May 23, 2024 |
| CAMPBELL REID TARLTON | — | Award / Grant | 165 | — | — | 15,340 | May 23, 2024 |
| Hicks Weston M | — | Award / Grant | 230 | — | — | 2,536 | May 23, 2024 |
| CAMPBELL REID TARLTON | — | Gift | 55 | — | — | 15,175 | Mar 21, 2024 |
| Rountree George Manning | Chief Executive Officer | Award / Grant | 1,800 | — | — | 6,500 | Feb 22, 2024 |
| Caffrey Liam P | EVP& Chief Financial Officer | Award / Grant | 1,125 | — | — | 3,625 | Feb 22, 2024 |
| SEELIG ROBERT LAWRENCE | EVP & General Counsel | Award / Grant | 900 | — | — | 3,150 | Feb 22, 2024 |
| Hildreth Michaela | MD & Chief Accounting Officer | Award / Grant | 600 | — | — | 1,950 | Feb 22, 2024 |
| CAMPBELL REID TARLTON | — | Award / Grant | 45 | — | — | 15,230 | Feb 22, 2024 |
| Rountree George Manning | Chief Executive Officer | Tax Withholding | 1,068 | $1,505.01 | $1,607,351 | 17,176 | Jan 1, 2024 |
| CAMPBELL REID TARLTON | President | Tax Withholding | 710 | $1,505.01 | $1,068,557 | 15,185 | Jan 1, 2024 |
| SEELIG ROBERT LAWRENCE | EVP & General Counsel | Tax Withholding | 399 | $1,505.01 | $600,499 | 16,551 | Jan 1, 2024 |
| Hildreth Michaela | MD & Chief Accounting Officer | Tax Withholding | 261 | $1,505.01 | $392,808 | 1,873 | Jan 1, 2024 |
| Hildreth Michaela | MD & Chief Accounting Officer | Gift | 100 | — | — | 1,534 | Dec 1, 2023 |
| Hicks Weston M | — | Purchase | 579 | $1,479.88 | $856,851 | 2,057 | Nov 17, 2023 |
| Hicks Weston M | — | Purchase | 52 | $1,476.15 | $76,760 | 1,358 | Nov 17, 2023 |
| Carlson Peter M | — | Award / Grant | 180 | — | — | 968 | May 25, 2023 |