WTM - CIK 0000776867
WHITE MOUNTAINS INSURANCE GROUP LTD has filed 1,719 documents with the SEC 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.
| Filing | Type | Filed | Period covered |
|---|---|---|---|
| Major company event | 8-K | 2000-10-20 | 2000-10-20 |
| Major company event | 8-K | 2000-10-20 | 2000-10-19 |
| Major company event | 8-K | 2000-09-25 | 2000-09-24 |
| SC TO-I/A | - | 2000-09-25 | - |
| SC TO-I/A | - | 2000-09-18 | - |
| SC TO-I/A | - | 2000-09-12 | - |
| SC TO-I | - | 2000-08-21 | - |
| Institutional holdings | 13F-HR | 2000-08-14 | 2000-06-30 |
| Quarterly report | 10-Q | 2000-08-11 | 2000-06-30 |
| Employee plan annual report | 11-K | 2000-08-02 | 1999-12-31 |
| Passive ownership stake | SC 13G | 2000-07-13 | - |
| Activist ownership stake | SC 13D | 2000-07-06 | - |
| Major company event (amended) | 8-K/A | 2000-07-06 | 2000-03-14 |
| NT 11-K | - | 2000-06-23 | 1999-12-31 |
| Institutional holdings | 13F-HR | 2000-05-12 | 2000-03-31 |
| Quarterly report | 10-Q | 2000-05-12 | 2000-03-31 |
| Major company event (amended) | 8-K/A | 2000-05-05 | 2000-03-14 |
| Major company event | 8-K | 2000-04-06 | 1999-12-30 |
| Annual report | 10-K | 2000-03-28 | 1999-12-31 |
| Proxy statement | DEF 14A | 2000-03-27 | 2000-05-22 |
| Major company event | 8-K | 2000-03-21 | 2000-03-14 |
| S-8 POS | - | 2000-02-15 | - |
| S-8 POS | - | 2000-02-15 | - |
| S-8 POS | - | 2000-02-15 | - |
| 13F-NT | - | 2000-02-14 | 1999-12-31 |
| Passive ownership stake (update) | SC 13G/A | 2000-02-09 | - |
| Passive ownership stake | SC 13G | 2000-01-31 | - |
| Major company event | 8-K | 2000-01-27 | 2000-01-10 |
| Major company event | 8-K | 2000-01-11 | 1999-12-30 |
| 8-A12B | - | 1999-12-16 | - |
| Activist ownership stake | SC 13D | 1999-12-09 | - |
| Quarterly report | 10-Q | 1999-11-12 | 1999-09-30 |
| Institutional holdings | 13F-HR | 1999-11-12 | 1999-09-30 |
| Major company event | 8-K | 1999-11-01 | 1999-10-27 |
| Employee stock plan | S-8 | 1999-10-20 | - |
| Employee stock plan | S-8 | 1999-10-20 | - |
| Employee stock plan | S-8 | 1999-10-20 | - |
| Employee stock plan | S-8 | 1999-10-20 | - |
| Major company event | 8-K | 1999-10-18 | 1999-10-15 |
| DEFM14A | - | 1999-09-27 | - |
| Major company event | 8-K | 1999-09-22 | 1999-08-05 |
| Activist ownership stake (update) | SC 13D/A | 1999-09-10 | - |
| Activist ownership stake (update) | SC 13D/A | 1999-08-24 | - |
| Major company event (amended) | 8-K/A | 1999-08-17 | 1999-06-17 |
| Quarterly report | 10-Q | 1999-08-16 | 1999-06-30 |
| Institutional holdings | 13F-HR | 1999-08-12 | 1999-06-30 |
| Activist ownership stake | SC 13D | 1999-07-13 | - |
| Employee stock plan | S-8 | 1999-07-09 | - |
| Employee plan annual report | 11-K | 1999-07-09 | 1998-12-31 |
| Passive ownership stake (update) | SC 13G/A | 1999-07-09 | - |