Data spanning the past 90 days through February 19, 2026 reveals that White Mountains Insurance's three principal insider shareholders consist of Evp & General Counsel Robert Lawrence Seelig (17.91K shares), Chief Executive Officer George Manning Rountree (13.81K shares), Director Reid Tarlton Campbell (10.44K shares).
| Holder | Position | Shares | Report Date |
|---|---|---|---|
| Robert Lawrence Seelig | Evp & General Counsel | 17,907 | 02 Jan, 2026 |
| George Manning Rountree | Chief Executive Officer | 13,809 | 22 Dec, 2025 |
| Reid Tarlton Campbell | 10,440 | 22 Dec, 2025 | |
| Morgan W Davis | 7,739 | 29 Dec, 2022 | |
| Weston M Hicks | 2,746 | 22 May, 2025 | |
| Michaela Hildreth | Md & Chief Accounting Officer | 2,491 | 02 Jan, 2026 |
| David Allen Tanner | 2,104 | 10 Nov, 2025 | |
| Giles E Harrison | Evp & Chief Strategy Officer | 1,900 | 27 Feb, 2025 |
| Mary C Choksi | 1,858 | 22 May, 2025 | |
| Liam P Caffrey | Chief Executive Officer | 1,655 | 02 Jan, 2026 |
| Philip A Gelston | 1,568 | 16 Dec, 2025 | |
| Margaret Dillon | 945 | 22 May, 2025 | |
| Suzanne F. Shank | 871 | 23 May, 2025 | |
| Michael A Papamichael | Chief Financial Officer | 772 | 02 Jan, 2026 |
| Peter M Carlson | 717 | 22 May, 2025 | |
| Steven Yi | 525 | 23 May, 2025 |
* Please note that the shares above only reflect shares from the fund portfolio and the institutional portfolio. Shares from the personal portfolio are excluded from this Institutional Ownership Page. See these insiders' latest transactions here on Insider Page.
| Transaction Date | Insider Name | Security Class | Transaction Type | Shares Traded | Price | Shares Remaining | Ownership | Code |
|---|---|---|---|---|---|---|---|---|
| 01 Jan, 2026 | Robert Lawrence Seelig | Common Shares | D | 398 | $2,078.03 | 17,907 | D | F |
| 01 Jan, 2026 | Michaela Hildreth | Common Shares | D | 274 | $2,078.03 | 2,491 | D | F |
| 01 Jan, 2026 | Liam P Caffrey | Common Shares | D | 425 | $2,078.03 | 1,655 | D | F |
| 01 Jan, 2026 | Michael A Papamichael | Common Shares | D | 131 | $2,078.03 | 772 | D | F |
| 23 Dec, 2025 | Michaela Hildreth | Common Shares | D | 60 | $0.00 | 2,165 | D | G |
| 19 Dec, 2025 | Reid Tarlton Campbell | Common Shares | D | 5,000 | $2,050.00 | 10,440 | D | S |
| 19 Dec, 2025 | Reid Tarlton Campbell | Common Shares | D | 5,000 | $0.00 | 10,440 | D | S |
| 19 Dec, 2025 | George Manning Rountree | Common Shares | D | 5,000 | $2,050.00 | 13,809 | D | S |
| 19 Dec, 2025 | George Manning Rountree | - | - | 13,809 | D | |||
| 16 Dec, 2025 | Philip A Gelston | - | - | 1,568 | D | |||
| 16 Dec, 2025 | Philip A Gelston | Common Shares | D | 165 | $2,048.51 | 1,568 | D | S |
| 25 Nov, 2025 | Reid Tarlton Campbell | Common Shares | D | 50 | $0.00 | 15,440 | D | G |
| 25 Nov, 2025 | Reid Tarlton Campbell | - | - | 15,440 | D | |||
| 10 Nov, 2025 | David Allen Tanner | - | - | 2,104 | D | |||
| 10 Nov, 2025 | David Allen Tanner | Common Shares | D | 4 | $0.00 | 2,104 | D | G |
| 22 May, 2025 | Weston M Hicks | - | - | 2,746 | D | |||
| 22 May, 2025 | Weston M Hicks | Common Shares | A | 210 | $0.00 | 2,746 | D | A |
| 22 May, 2025 | Mary C Choksi | Common Shares | A | 150 | $0.00 | 1,858 | D | A |
| 22 May, 2025 | David Allen Tanner | Common Shares | A | 150 | $0.00 | 2,108 | D | A |
| 22 May, 2025 | Reid Tarlton Campbell | Common Shares | A | 150 | $0.00 | 15,490 | D | A |