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 |
|---|---|---|---|
| Quarterly report | 10-Q | 1997-05-13 | 1997-03-31 |
| Proxy statement | DEF 14A | 1997-04-01 | 1997-05-29 |
| Annual report | 10-K | 1997-03-28 | 1996-12-31 |
| Activist ownership stake (update) | SC 13D/A | 1997-03-18 | - |
| 424B3 | - | 1997-03-05 | - |
| Passive ownership stake (update) | SC 13G/A | 1997-02-21 | - |
| Passive ownership stake (update) | SC 13G/A | 1997-02-21 | - |
| Passive ownership stake (update) | SC 13G/A | 1997-02-14 | - |
| Passive ownership stake | SC 13G | 1997-02-13 | - |
| Major company event | 8-K | 1997-01-31 | 1997-01-24 |
| Quarterly report | 10-Q | 1996-11-12 | 1996-09-30 |
| Employee stock plan | S-8 | 1996-09-30 | - |
| Employee plan annual report | 11-K | 1996-09-27 | 1995-12-31 |
| Major company event (amended) | 8-K/A | 1996-08-20 | 1996-06-19 |
| Quarterly report | 10-Q | 1996-08-13 | 1996-06-30 |
| Major company event | 8-K | 1996-06-28 | 1996-06-19 |
| Activist ownership stake (update) | SC 13D/A | 1996-06-27 | - |
| SC 13E4 | - | 1996-06-18 | - |
| SC 13E4/A | - | 1996-06-07 | - |
| SC 13E4 | - | 1996-05-20 | - |
| Quarterly report | 10-Q | 1996-05-15 | 1996-03-31 |
| 10-K405 | - | 1996-03-29 | 1995-12-31 |
| Proxy statement | DEF 14A | 1996-03-29 | 1996-05-16 |
| Activist ownership stake (update) | SC 13D/A | 1996-03-11 | - |
| Activist ownership stake (update) | SC 13D/A | 1996-03-04 | - |
| Activist ownership stake (update) | SC 13D/A | 1996-02-09 | - |
| Passive ownership stake (update) | SC 13G/A | 1996-02-05 | - |
| Activist ownership stake (update) | SC 13D/A | 1996-02-02 | - |
| Activist ownership stake (update) | SC 13D/A | 1996-01-19 | - |
| Passive ownership stake (update) | SC 13G/A | 1996-01-19 | - |
| SC 13E4/A | - | 1996-01-12 | - |
| SC 13E4/A | - | 1995-12-27 | - |
| Major company event | 8-K | 1995-12-05 | 1995-12-01 |
| SC 13E4 | - | 1995-12-04 | - |
| Activist ownership stake (update) | SC 13D/A | 1995-11-16 | - |
| Activist ownership stake (update) | SC 13D/A | 1995-11-15 | - |
| Activist ownership stake (update) | SC 13D/A | 1995-11-15 | - |
| Quarterly report | 10-Q | 1995-11-14 | 1995-09-30 |
| Activist ownership stake (update) | SC 13D/A | 1995-10-12 | - |
| Activist ownership stake (update) | SC 13D/A | 1995-09-18 | - |
| Activist ownership stake | SC 13D | 1995-09-08 | - |
| Quarterly report | 10-Q | 1995-08-11 | 1995-06-30 |
| Activist ownership stake | SC 13D | 1995-07-13 | - |
| Activist ownership stake | SC 13D | 1995-06-09 | - |
| Annual report (amended) | 10-K/A | 1995-05-24 | 1994-10-31 |
| Quarterly report | 10-Q | 1995-05-12 | 1995-03-31 |
| Activist ownership stake (update) | SC 13D/A | 1995-05-02 | - |
| Proxy statement | DEF 14A | 1995-03-30 | 1995-05-25 |
| 10-K405 | - | 1995-03-30 | 1994-12-31 |
| SC 13E4 | - | 1995-03-28 | - |