White Mountains Insurance Group Ltd SEC filings WTM
White Mountains Insurance Group Ltd has 1,005 filings in SEC EDGAR's recent list, going back to Mar 29, 2010. Its latest annual report, Form ARS, was filed on Apr 1, 2026 for the period ended Dec 31, 2025. The latest quarterly report (Form 10-Q) was filed on Nov 5, 2026, covering the quarter ended Sep 30, 2026. The most recent current report (Form 8-K) was filed on Nov 5, 2026 (results of operations). The company's fiscal year ends on December 31.
| Form | Description | Filed | Period |
|---|---|---|---|
| SCHEDULE 13D/A | Amended ownership over 5% (active) | Nov 5, 2026 | — |
| 4 | Insider transaction | Nov 5, 2026 | Nov 4, 2026 |
| SCHEDULE 13D/A | Amended ownership over 5% (active) | Oct 30, 2026 | — |
| 4 | Insider transaction | Aug 31, 2026 | Aug 31, 2026 |
| 4 | Insider transaction | Aug 27, 2026 | Aug 26, 2026 |
| 3 | Initial insider ownership | Aug 27, 2026 | Aug 26, 2026 |
| 13F-HR | Filing | Aug 12, 2026 | Jun 30, 2026 |
| 4 | Insider transaction | May 22, 2026 | May 21, 2026 |
| 4 | Insider transaction | May 22, 2026 | May 21, 2026 |
| 4 | Insider transaction | May 22, 2026 | May 21, 2026 |
| 4 | Insider transaction | May 22, 2026 | May 21, 2026 |
| 4 | Insider transaction | May 22, 2026 | May 21, 2026 |
| 4 | Insider transaction | May 22, 2026 | May 21, 2026 |
| 3 | Initial insider ownership | May 22, 2026 | May 21, 2026 |
| 4 | Insider transaction | May 22, 2026 | May 21, 2026 |
| 4 | Insider transaction | May 22, 2026 | May 21, 2026 |
| 4 | Insider transaction | May 22, 2026 | May 21, 2026 |
| 13F-HR | Filing | May 12, 2026 | Mar 31, 2026 |
| SCHEDULE 13G/A | Amended ownership over 5% (passive) | May 7, 2026 | — |
| SCHEDULE 13D/A | Amended ownership over 5% (active) | May 1, 2026 | — |
| SCHEDULE 13G | Ownership over 5% (passive) | Apr 30, 2026 | — |
| SCHEDULE 13G/A | Amended ownership over 5% (passive) | Mar 27, 2026 | — |
| 4 | Insider transaction | Mar 20, 2026 | Mar 19, 2026 |
| 4 | Insider transaction | Mar 5, 2026 | Mar 4, 2026 |
| 4 | Insider transaction | Feb 27, 2026 | Feb 25, 2026 |
| 4 | Insider transaction | Feb 27, 2026 | Feb 25, 2026 |
| 4 | Insider transaction | Feb 27, 2026 | Feb 25, 2026 |
| 4 | Insider transaction | Feb 27, 2026 | Feb 25, 2026 |
| 4 | Insider transaction | Feb 27, 2026 | Feb 25, 2026 |
| 13F-HR | Filing | Feb 12, 2026 | Dec 31, 2025 |
| SCHEDULE 13G/A | Amended ownership over 5% (passive) | Feb 12, 2026 | — |
| SCHEDULE 13G | Ownership over 5% (passive) | Feb 5, 2026 | — |
| 4 | Insider transaction | Jan 5, 2026 | Jan 1, 2026 |
| 4 | Insider transaction | Jan 2, 2026 | Jan 1, 2026 |
| 3 | Initial insider ownership | Jan 2, 2026 | Jan 1, 2026 |
| 4 | Insider transaction | Jan 2, 2026 | Jan 1, 2026 |
| 4 | Insider transaction | Jan 2, 2026 | Jan 1, 2026 |
| 4 | Insider transaction | Dec 23, 2025 | Dec 23, 2025 |
| 4/A | Amended statement of changes in beneficial ownership of securities | Dec 22, 2025 | Dec 19, 2025 |
| 4 | Insider transaction | Dec 22, 2025 | Dec 19, 2025 |
| 4 | Insider transaction | Dec 22, 2025 | Dec 19, 2025 |
| 4 | Insider transaction | Dec 16, 2025 | Dec 16, 2025 |
| 4 | Insider transaction | Nov 26, 2025 | Nov 25, 2025 |
| 13F-HR | Filing | Nov 13, 2025 | Sep 30, 2025 |
| 4 | Insider transaction | Nov 10, 2025 | Nov 10, 2025 |
| SCHEDULE 13G/A | Amended ownership over 5% (passive) | Nov 7, 2025 | — |
| 13F-HR | Filing | Aug 11, 2025 | Jun 30, 2025 |
| SCHEDULE 13D/A | Amended ownership over 5% (active) | Aug 8, 2025 | — |
| SCHEDULE 13G/A | Amended ownership over 5% (passive) | Aug 7, 2025 | — |
| 4 | Insider transaction | May 27, 2025 | May 22, 2025 |
| 4 | Insider transaction | May 23, 2025 | May 22, 2025 |
| 4 | Insider transaction | May 23, 2025 | May 22, 2025 |
| 4 | Insider transaction | May 23, 2025 | May 22, 2025 |
| 4 | Insider transaction | May 23, 2025 | May 22, 2025 |
| 4 | Insider transaction | May 23, 2025 | May 22, 2025 |
| 4 | Insider transaction | May 23, 2025 | May 22, 2025 |
| 4 | Insider transaction | May 23, 2025 | May 22, 2025 |
| 4 | Insider transaction | May 23, 2025 | May 22, 2025 |
| 13F-HR | Filing | May 12, 2025 | Mar 31, 2025 |
| 4 | Insider transaction | Feb 28, 2025 | Feb 26, 2025 |
| 4 | Insider transaction | Feb 28, 2025 | Feb 26, 2025 |
| 4 | Insider transaction | Feb 28, 2025 | Feb 26, 2025 |
| 4 | Insider transaction | Feb 28, 2025 | Feb 26, 2025 |
| 4 | Insider transaction | Feb 28, 2025 | Feb 26, 2025 |
| 13F-HR | Filing | Feb 12, 2025 | Dec 31, 2024 |
| 4 | Insider transaction | Jan 3, 2025 | Jan 1, 2025 |
| 4 | Insider transaction | Jan 3, 2025 | Jan 1, 2025 |
| 4 | Insider transaction | Jan 3, 2025 | Jan 1, 2025 |
| 4 | Insider transaction | Jan 3, 2025 | Jan 1, 2025 |
| 4 | Insider transaction | Dec 2, 2024 | Nov 29, 2024 |
| SC 13G/A | Amended ownership over 5% (passive) | Nov 12, 2024 | — |
| 13F-HR | Filing | Nov 12, 2024 | Sep 30, 2024 |
| 13F-HR | Filing | Aug 8, 2024 | Jun 30, 2024 |
| 4 | Insider transaction | Jun 10, 2024 | Jun 10, 2024 |
| 3 | Initial insider ownership | Jun 10, 2024 | Jun 10, 2024 |
| 4 | Insider transaction | May 24, 2024 | May 23, 2024 |
| 4 | Insider transaction | May 24, 2024 | May 23, 2024 |
| 4 | Insider transaction | May 24, 2024 | May 23, 2024 |
| 4 | Insider transaction | May 24, 2024 | May 23, 2024 |
| 4 | Insider transaction | May 24, 2024 | May 23, 2024 |
| 4 | Insider transaction | May 24, 2024 | May 23, 2024 |
| 4 | Insider transaction | May 24, 2024 | May 23, 2024 |
| 4 | Insider transaction | May 24, 2024 | May 23, 2024 |
| 4 | Insider transaction | May 24, 2024 | May 23, 2024 |
| SC 13D/A | Amended ownership over 5% (active) | May 9, 2024 | — |
| 4 | Insider transaction | May 9, 2024 | May 7, 2024 |
| 13F-HR | Filing | May 9, 2024 | Mar 31, 2024 |
| SC 13D/A | Amended ownership over 5% (active) | May 3, 2024 | — |
| 4 | Insider transaction | Mar 21, 2024 | Mar 21, 2024 |
| 4 | Insider transaction | Feb 23, 2024 | Feb 22, 2024 |
| 4 | Insider transaction | Feb 23, 2024 | Feb 22, 2024 |
| 4 | Insider transaction | Feb 23, 2024 | Feb 22, 2024 |
| 4 | Insider transaction | Feb 23, 2024 | Feb 22, 2024 |
| 4 | Insider transaction | Feb 23, 2024 | Feb 22, 2024 |
| SC 13G/A | Amended ownership over 5% (passive) | Feb 13, 2024 | — |
| 13F-HR | Filing | Feb 13, 2024 | Dec 31, 2023 |
| SC 13G/A | Amended ownership over 5% (passive) | Feb 12, 2024 | — |
| SC 13G/A | Amended ownership over 5% (passive) | Feb 9, 2024 | — |
| SC 13G/A | Amended ownership over 5% (passive) | Feb 9, 2024 | — |
| SC 13D/A | Amended ownership over 5% (active) | Jan 3, 2024 | — |
| 4 | Insider transaction | Jan 2, 2024 | Jan 1, 2024 |
| 4 | Insider transaction | Jan 2, 2024 | Jan 1, 2024 |
| 4 | Insider transaction | Jan 2, 2024 | Jan 1, 2024 |
| 4 | Insider transaction | Jan 2, 2024 | Jan 1, 2024 |
| 4 | Insider transaction | Dec 1, 2023 | Dec 1, 2023 |
| 4/A | Amended statement of changes in beneficial ownership of securities | Nov 20, 2023 | Nov 17, 2023 |
| 4 | Insider transaction | Nov 20, 2023 | Nov 17, 2023 |
| 13F-HR | Filing | Nov 9, 2023 | Sep 30, 2023 |
| SC 13D/A | Amended ownership over 5% (active) | Nov 2, 2023 | — |
| 13F-HR | Filing | Aug 10, 2023 | Jun 30, 2023 |
| SC 13D | Ownership over 5% (active) | Jun 30, 2023 | — |
| 4 | Insider transaction | Jun 30, 2023 | Jun 30, 2023 |
| SC 13G/A | Amended ownership over 5% (passive) | Jun 8, 2023 | — |
| 4 | Insider transaction | May 30, 2023 | May 25, 2023 |
| 4 | Insider transaction | May 26, 2023 | May 25, 2023 |
| 4 | Insider transaction | May 26, 2023 | May 25, 2023 |
| 4 | Insider transaction | May 26, 2023 | May 25, 2023 |
| 4 | Insider transaction | May 26, 2023 | May 23, 2023 |
| 4 | Insider transaction | May 26, 2023 | May 25, 2023 |
| 4 | Insider transaction | May 26, 2023 | May 25, 2023 |
| 4 | Insider transaction | May 26, 2023 | May 25, 2023 |
| 3 | Initial insider ownership | May 26, 2023 | May 25, 2023 |
| 13F-HR | Filing | May 11, 2023 | Mar 31, 2023 |
| SC 13G/A | Amended ownership over 5% (passive) | Mar 10, 2023 | — |
| 4 | Insider transaction | Feb 24, 2023 | Feb 22, 2023 |
| 4 | Insider transaction | Feb 24, 2023 | Feb 22, 2023 |
| 4 | Insider transaction | Feb 24, 2023 | Feb 22, 2023 |
| 4 | Insider transaction | Feb 24, 2023 | Feb 22, 2023 |
| 4 | Insider transaction | Feb 23, 2023 | Feb 22, 2023 |
| 3 | Initial insider ownership | Feb 23, 2023 | Feb 22, 2023 |
| SC 13G | Ownership over 5% (passive) | Feb 14, 2023 | — |
| 13F-HR | Filing | Feb 13, 2023 | Dec 31, 2022 |
| SC 13G | Ownership over 5% (passive) | Feb 10, 2023 | — |
| SC 13G | Ownership over 5% (passive) | Feb 10, 2023 | — |
| SC 13G/A | Amended ownership over 5% (passive) | Feb 10, 2023 | — |
| SC 13G/A | Amended ownership over 5% (passive) | Feb 9, 2023 | — |
| SC 13G | Ownership over 5% (passive) | Feb 8, 2023 | — |
| SC 13G/A | Amended ownership over 5% (passive) | Feb 6, 2023 | — |
| 4 | Insider transaction | Jan 3, 2023 | Jan 1, 2023 |
| 4 | Insider transaction | Jan 3, 2023 | Jan 1, 2023 |
| 4 | Insider transaction | Jan 3, 2023 | Jan 1, 2023 |
| 4 | Insider transaction | Jan 3, 2023 | Jan 1, 2023 |
| 4 | Insider transaction | Dec 29, 2022 | Dec 28, 2022 |
| 4 | Insider transaction | Dec 29, 2022 | Dec 28, 2022 |
| 4 | Insider transaction | Dec 27, 2022 | Dec 22, 2022 |
| 13F-HR | Filing | Nov 9, 2022 | Sep 30, 2022 |
| 4 | Insider transaction | Sep 22, 2022 | Sep 20, 2022 |
| 4 | Insider transaction | Sep 22, 2022 | Sep 20, 2022 |
| 13F-HR | Filing | Aug 12, 2022 | Jun 30, 2022 |
| 4 | Insider transaction | Jun 2, 2022 | Jun 1, 2022 |
| 4 | Insider transaction | Jun 1, 2022 | May 31, 2022 |
| 4 | Insider transaction | May 27, 2022 | May 26, 2022 |
| 4 | Insider transaction | May 27, 2022 | May 26, 2022 |
| 4 | Insider transaction | May 27, 2022 | May 26, 2022 |
| 4 | Insider transaction | May 27, 2022 | May 26, 2022 |
| 4 | Insider transaction | May 27, 2022 | May 26, 2022 |
| 4 | Insider transaction | May 27, 2022 | May 26, 2022 |
| 4 | Insider transaction | May 27, 2022 | May 26, 2022 |
| 4 | Insider transaction | May 17, 2022 | May 16, 2022 |
| 13F-HR | Filing | May 12, 2022 | Mar 31, 2022 |
| SC 13G/A | Amended ownership over 5% (passive) | May 6, 2022 | — |
| 3 | Initial insider ownership | Mar 7, 2022 | Mar 1, 2022 |
| 4 | Insider transaction | Feb 28, 2022 | Feb 25, 2022 |
| 4 | Insider transaction | Feb 28, 2022 | Feb 25, 2022 |
| 4 | Insider transaction | Feb 28, 2022 | Feb 25, 2022 |
| SC 13G/A | Amended ownership over 5% (passive) | Feb 14, 2022 | — |
| 13F-HR | Filing | Feb 11, 2022 | Dec 31, 2021 |
| SC 13G/A | Amended ownership over 5% (passive) | Feb 11, 2022 | — |
| SC 13G/A | Amended ownership over 5% (passive) | Feb 10, 2022 | — |
| SC 13G/A | Amended ownership over 5% (passive) | Feb 9, 2022 | — |
| SC 13G/A | Amended ownership over 5% (passive) | Feb 4, 2022 | — |
| 4 | Insider transaction | Jan 4, 2022 | Jan 1, 2022 |
| 4 | Insider transaction | Jan 4, 2022 | Jan 1, 2022 |
| 4 | Insider transaction | Jan 4, 2022 | Jan 1, 2022 |
| SC 13G/A | Amended ownership over 5% (passive) | Dec 10, 2021 | — |
| 4 | Insider transaction | Dec 10, 2021 | Dec 8, 2021 |
| 13F-HR | Filing | Nov 12, 2021 | Sep 30, 2021 |
| 4 | Insider transaction | Oct 12, 2021 | Oct 10, 2021 |
| 3 | Initial insider ownership | Oct 12, 2021 | Oct 10, 2021 |
| 13F-HR | Filing | Aug 12, 2021 | Jun 30, 2021 |
| 4 | Insider transaction | Jun 21, 2021 | Jun 18, 2021 |
| 4 | Insider transaction | Jun 8, 2021 | Jun 7, 2021 |
| 4 | Insider transaction | May 28, 2021 | May 27, 2021 |
| 4 | Insider transaction | May 28, 2021 | May 27, 2021 |
| 3 | Initial insider ownership | May 28, 2021 | May 27, 2021 |
| 4 | Insider transaction | May 28, 2021 | May 27, 2021 |
| 4 | Insider transaction | May 28, 2021 | May 27, 2021 |
| 4 | Insider transaction | May 28, 2021 | May 27, 2021 |
| 4 | Insider transaction | May 28, 2021 | May 27, 2021 |
| 3 | Initial insider ownership | May 20, 2021 | May 14, 2021 |
| 13F-HR | Filing | May 14, 2021 | Mar 31, 2021 |
| 4 | Insider transaction | Mar 25, 2021 | Mar 23, 2021 |
| 4 | Insider transaction | Mar 18, 2021 | Mar 17, 2021 |
| 4 | Insider transaction | Feb 26, 2021 | Feb 25, 2021 |
| 4 | Insider transaction | Feb 26, 2021 | Feb 25, 2021 |
| 4 | Insider transaction | Feb 26, 2021 | Feb 25, 2021 |
| SC 13G | Ownership over 5% (passive) | Feb 12, 2021 | — |
| 13F-HR | Filing | Feb 12, 2021 | Dec 31, 2020 |
| SC 13G | Ownership over 5% (passive) | Feb 12, 2021 | — |
| 4 | Insider transaction | Feb 11, 2021 | Feb 9, 2021 |
Showing 200 filings, the most recent 200. Main filings leave out insider and ownership forms such as Form 4; choose a type above to see them. Each form opens on SEC.gov. Older filings are on SEC EDGAR.
New to this? Read What Are SEC Filings? 10-K, 10-Q, 8-K and Other Forms Explained.
Company profile
- Industry
- Fire, Marine & Casualty Insurance (SIC 6331)
- Listed as
- WTM (NYSE)
- Fiscal year ends
- December 31
- Incorporated in
- Bermuda
- Headquarters
- Hanover, NH
- SEC filer status
- Large accelerated filer
- SEC CIK
- 776867
- Former names
- WHITE MOUNTAINS INSURANCE GROUP INC (until Oct 20, 1999); FUND AMERICAN ENTERPRISES HOLDINGS INC (until Feb 10, 1999)
Other Fire, Marine & Casualty Insurance companies
Source: SEC EDGAR filings. This is company-reported data, not investment advice.