WTM - Company ID 0000776867
WHITE MOUNTAINS INSURANCE GROUP LTD has filed 1,716 public company documents between 1994 and 2026. The most frequent type is insider trade (634 filings), alongside the regular cadence of annual reports, quarterly reports, and event disclosures every public company must make. Use the filters to focus on one filing type, or flip the sort to trace the company's history from its earliest paperwork.
Data parsed from SEC EDGAR XBRL filings. See the full market cap rankings.
| Type | Filing | Filed | Period covered | Open |
|---|---|---|---|---|
| 4 | Insider trade | 1mo ago2026-05-22 | 2026-05-21 | View filing |
| 4 | Insider trade | 1mo ago2026-05-22 | 2026-05-21 | View filing |
| 4 | Insider trade | 1mo ago2026-05-22 | 2026-05-21 | View filing |
| 4 | Insider trade | 1mo ago2026-05-22 | 2026-05-21 | View filing |
| 4 | Insider trade | 1mo ago2026-05-22 | 2026-05-21 | View filing |
| 4 | Insider trade | 1mo ago2026-05-22 | 2026-05-21 | View filing |
| 3 | New insider ownership | 1mo ago2026-05-22 | 2026-05-21 | View filing |
| 4 | Insider trade | 1mo ago2026-05-22 | 2026-05-21 | View filing |
| 4 | Insider trade | 1mo ago2026-05-22 | 2026-05-21 | View filing |
| 4 | Insider trade | 1mo ago2026-05-22 | 2026-05-21 | View filing |
| 8-K | Major company event | 1mo ago2026-05-21 | 2026-05-21 | View filing |
| 8-K | Major company event | 1mo ago2026-05-15 | 2026-05-14 | View filing |
| 13F-HR | Institutional holdings | 1mo ago2026-05-12 | 2026-03-31 | View filing |
| SCHEDULE 13G/A | SCHEDULE 13G/A | 2mo ago2026-05-07 | - | View filing |
| 10-Q | Quarterly report | 2mo ago2026-05-06 | 2026-03-31 | View filing |
| 8-K | Major company event | 2mo ago2026-05-06 | 2026-05-06 | View filing |
| SCHEDULE 13G | SCHEDULE 13G | 2mo ago2026-04-30 | - | View filing |
| 8-K | Major company event | 3mo ago2026-04-01 | 2026-04-01 | View filing |
| ARS | Annual report to shareholders | 3mo ago2026-04-01 | 2025-12-31 | View filing |
| DEF 14A | Proxy statement | 3mo ago2026-04-01 | 2026-05-21 | View filing |
| SCHEDULE 13G/A | SCHEDULE 13G/A | 3mo ago2026-03-27 | - | View filing |
| 4 | Insider trade | 3mo ago2026-03-20 | 2026-03-19 | View filing |
| 4 | Insider trade | 4mo ago2026-03-05 | 2026-03-04 | View filing |
| 10-K | Annual report | 4mo ago2026-02-27 | 2025-12-31 | View filing |
| 4 | Insider trade | 4mo ago2026-02-27 | 2026-02-25 | View filing |
| 4 | Insider trade | 4mo ago2026-02-27 | 2026-02-25 | View filing |
| 4 | Insider trade | 4mo ago2026-02-27 | 2026-02-25 | View filing |
| 4 | Insider trade | 4mo ago2026-02-27 | 2026-02-25 | View filing |
| 4 | Insider trade | 4mo ago2026-02-27 | 2026-02-25 | View filing |
| 8-K | Major company event | 4mo ago2026-02-26 | 2026-02-26 | View filing |
| 13F-HR | Institutional holdings | 4mo ago2026-02-12 | 2025-12-31 | View filing |
| 8-K | Major company event | 5mo ago2026-02-06 | 2026-02-06 | View filing |
| SCHEDULE 13G | SCHEDULE 13G | 5mo ago2026-02-05 | - | View filing |
| 8-K | Major company event | 6mo ago2026-01-07 | 2026-01-07 | View filing |
| 4 | Insider trade | 6mo ago2026-01-05 | 2026-01-01 | View filing |
| 4 | Insider trade | 6mo ago2026-01-02 | 2026-01-01 | View filing |
| 3 | New insider ownership | 6mo ago2026-01-02 | 2026-01-01 | View filing |
| 4 | Insider trade | 6mo ago2026-01-02 | 2026-01-01 | View filing |
| 4 | Insider trade | 6mo ago2026-01-02 | 2026-01-01 | View filing |
| SC TO-I/A | SC TO-I/A | 6mo ago2025-12-29 | - | View filing |
| 4 | Insider trade | 6mo ago2025-12-23 | 2025-12-23 | View filing |
| SC TO-I/A | SC TO-I/A | 6mo ago2025-12-22 | - | View filing |
| 4/A | Insider trade (amended) | 6mo ago2025-12-22 | 2025-12-19 | View filing |
| 4 | Insider trade | 6mo ago2025-12-22 | 2025-12-19 | View filing |
| 4 | Insider trade | 6mo ago2025-12-22 | 2025-12-19 | View filing |
| 4 | Insider trade | 6mo ago2025-12-16 | 2025-12-16 | View filing |
| 8-K | Major company event | 7mo ago2025-12-08 | 2025-12-05 | View filing |
| 4 | Insider trade | 7mo ago2025-11-26 | 2025-11-25 | View filing |
| SC TO-I | SC TO-I | 7mo ago2025-11-21 | - | View filing |
| 13F-HR | Institutional holdings | 7mo ago2025-11-13 | 2025-09-30 | View filing |