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 |
| 10-Q | Quarterly report | Nov 5, 2026 | Sep 30, 2026 |
| 8-K |
Current report
Results of operations
|
Nov 5, 2026 | Nov 5, 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 |
| 8-K |
Current report
Officer or director change
|
Aug 27, 2026 | Aug 26, 2026 |
| N-PX | Filing | Aug 26, 2026 | Jun 30, 2026 |
| 13F-HR | Filing | Aug 12, 2026 | Jun 30, 2026 |
| 10-Q | Quarterly report | Aug 6, 2026 | Jun 30, 2026 |
| 8-K |
Current report
Results of operations
|
Aug 6, 2026 | Aug 6, 2026 |
| 11-K | Employee savings plan report | Jun 30, 2026 | Dec 31, 2025 |
| 8-K |
Current report
Regulation FD disclosure
|
Jun 5, 2026 | Jun 5, 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 |
| 8-K |
Current report
Officer or director change, Shareholder vote results
|
May 21, 2026 | May 21, 2026 |
| 8-K |
Current report
Material agreement, New debt
|
May 15, 2026 | May 14, 2026 |
| 13F-HR | Filing | May 12, 2026 | Mar 31, 2026 |
| SCHEDULE 13G/A | Amended ownership over 5% (passive) | May 7, 2026 | — |
| 10-Q | Quarterly report | May 6, 2026 | Mar 31, 2026 |
| 8-K |
Current report
Results of operations
|
May 6, 2026 | May 6, 2026 |
| SCHEDULE 13D/A | Amended ownership over 5% (active) | May 1, 2026 | — |
| SCHEDULE 13G | Ownership over 5% (passive) | Apr 30, 2026 | — |
| 8-K |
Current report
Other events
|
Apr 1, 2026 | Apr 1, 2026 |
| ARS | Annual report to shareholders | Apr 1, 2026 | Dec 31, 2025 |
| DEF 14A | Proxy statement | Apr 1, 2026 | May 21, 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 |
| 10-K | Annual report | Feb 27, 2026 | Dec 31, 2025 |
| 8-K |
Current report
Other events
|
Feb 26, 2026 | Feb 26, 2026 |
| 13F-HR | Filing | Feb 12, 2026 | Dec 31, 2025 |
| SCHEDULE 13G/A | Amended ownership over 5% (passive) | Feb 12, 2026 | — |
| 8-K |
Current report
Results of operations
|
Feb 6, 2026 | Feb 6, 2026 |
| SCHEDULE 13G | Ownership over 5% (passive) | Feb 5, 2026 | — |
| 8-K |
Current report
Other events
|
Jan 7, 2026 | Jan 7, 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 |
| SC TO-I/A | Filing | Dec 29, 2025 | — |
| 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 |
| SC TO-I/A | Filing | Dec 22, 2025 | — |
| 4 | Insider transaction | Dec 16, 2025 | Dec 16, 2025 |
| 8-K |
Current report
Acquisition or sale of assets, Other events
|
Dec 8, 2025 | Dec 5, 2025 |
| 4 | Insider transaction | Nov 26, 2025 | Nov 25, 2025 |
| SC TO-I | Filing | Nov 21, 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 | — |
| 10-Q | Quarterly report | Nov 6, 2025 | Sep 30, 2025 |
| 8-K |
Current report
Results of operations
|
Nov 6, 2025 | Nov 6, 2025 |
| 8-K |
Current report
Material agreement
|
Oct 3, 2025 | Oct 2, 2025 |
| 8-K |
Current report
Other events
|
Sep 3, 2025 | Sep 2, 2025 |
| 8-K |
Current report
Officer or director change
|
Sep 2, 2025 | Sep 2, 2025 |
| N-PX | Filing | Aug 27, 2025 | Jun 30, 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 | — |
| 10-Q | Quarterly report | Aug 7, 2025 | Jun 30, 2025 |
| 8-K |
Current report
Results of operations
|
Aug 7, 2025 | Aug 7, 2025 |
| 8-K |
Current report
Other events
|
Jul 18, 2025 | Jul 18, 2025 |
| 8-K |
Current report
Other events
|
Jul 16, 2025 | Jul 16, 2025 |
| 11-K | Employee savings plan report | Jul 7, 2025 | Dec 31, 2024 |
| 8-K |
Current report
Material agreement
|
Jul 7, 2025 | Jul 4, 2025 |
| 8-K |
Current report
Regulation FD disclosure
|
Jun 6, 2025 | Jun 6, 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 |
| 8-K |
Current report
Shareholder vote results
|
May 22, 2025 | May 22, 2025 |
| 13F-HR | Filing | May 12, 2025 | Mar 31, 2025 |
| 10-Q | Quarterly report | May 7, 2025 | Mar 31, 2025 |
| 8-K |
Current report
Results of operations
|
May 7, 2025 | May 7, 2025 |
| 8-K |
Current report
Other events
|
Apr 10, 2025 | Apr 10, 2025 |
| ARS | Annual report to shareholders | Apr 2, 2025 | Dec 31, 2024 |
| DEF 14A | Proxy statement | Apr 2, 2025 | May 22, 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 |
| 10-K | Annual report | Feb 28, 2025 | Dec 31, 2024 |
| 13F-HR | Filing | Feb 12, 2025 | Dec 31, 2024 |
| 8-K |
Current report
Results of operations
|
Feb 7, 2025 | Feb 7, 2025 |
| 8-K |
Current report
Other events
|
Jan 8, 2025 | Jan 8, 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 | 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 |
| 10-Q | Quarterly report | Nov 6, 2024 | Sep 30, 2024 |
| 8-K |
Current report
Results of operations
|
Nov 6, 2024 | Nov 6, 2024 |
| N-PX | Filing | Aug 29, 2024 | Jun 30, 2024 |
| 13F-HR | Filing | Aug 8, 2024 | Jun 30, 2024 |
| 10-Q | Quarterly report | Aug 7, 2024 | Jun 30, 2024 |
| 8-K |
Current report
Results of operations
|
Aug 7, 2024 | Aug 7, 2024 |
| 4 | Insider transaction | Jun 10, 2024 | Jun 10, 2024 |
| 3 | Initial insider ownership | Jun 10, 2024 | Jun 10, 2024 |
| 8-K |
Current report
Regulation FD disclosure
|
Jun 7, 2024 | Jun 7, 2024 |
| 11-K | Employee savings plan report | May 31, 2024 | Dec 31, 2023 |
| 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 |
| 8-K |
Current report
Shareholder vote results
|
May 23, 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 |
| 10-Q | Quarterly report | May 9, 2024 | Mar 31, 2024 |
| 8-K |
Current report
Results of operations
|
May 9, 2024 | May 9, 2024 |
| SC 13D/A | Amended ownership over 5% (active) | May 3, 2024 | — |
| 8-K |
Current report
Officer or director change
|
Apr 10, 2024 | Apr 10, 2024 |
| ARS | Annual report to shareholders | Apr 4, 2024 | Dec 31, 2023 |
| DEF 14A | Proxy statement | Apr 4, 2024 | May 23, 2024 |
| 4 | Insider transaction | Mar 21, 2024 | Mar 21, 2024 |
| 10-K | Annual report | Feb 26, 2024 | Dec 31, 2023 |
| 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 |
| 8-K |
Current report
Officer or director change
|
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 | — |
| 8-K |
Current report
Results of operations
|
Feb 7, 2024 | Feb 7, 2024 |
| 8-K |
Current report
Other events
|
Jan 3, 2024 | Jan 2, 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 |
| 8-K |
Current report
Other events
|
Dec 21, 2023 | Dec 21, 2023 |
| 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 |
| 10-Q | Quarterly report | Nov 6, 2023 | Sep 30, 2023 |
| 8-K |
Current report
Results of operations
|
Nov 6, 2023 | Nov 6, 2023 |
| SC 13D/A | Amended ownership over 5% (active) | Nov 2, 2023 | — |
| 8-K |
Current report
Material agreement
|
Oct 20, 2023 | Oct 19, 2023 |
| 13F-HR | Filing | Aug 10, 2023 | Jun 30, 2023 |
| 10-Q | Quarterly report | Aug 7, 2023 | Jun 30, 2023 |
| 8-K |
Current report
Results of operations
|
Aug 7, 2023 | Aug 7, 2023 |
| SC 13D | Ownership over 5% (active) | Jun 30, 2023 | — |
| 4 | Insider transaction | Jun 30, 2023 | Jun 30, 2023 |
| SC TO-T/A | Filing | Jun 30, 2023 | — |
| SC TO-T/A | Filing | Jun 27, 2023 | — |
| 11-K | Employee savings plan report | Jun 15, 2023 | Dec 31, 2022 |
| SC 13G/A | Amended ownership over 5% (passive) | Jun 8, 2023 | — |
| 8-K |
Current report
Regulation FD disclosure
|
Jun 6, 2023 | Jun 6, 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 |
| SC TO-T | Filing | May 26, 2023 | — |
| 8-K |
Current report
Shareholder vote results
|
May 25, 2023 | May 25, 2023 |
| 8-K |
Current report
Officer or director change
|
May 25, 2023 | May 25, 2023 |
| 13F-HR | Filing | May 11, 2023 | Mar 31, 2023 |
| DEFA14A | Additional proxy material | May 10, 2023 | — |
| 10-Q | Quarterly report | May 9, 2023 | Mar 31, 2023 |
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.
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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.