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 |
|---|---|---|---|---|
| 13F-HR | Institutional holdings | 1mo ago2026-05-12 | 2026-03-31 | View filing |
| 13F-HR | Institutional holdings | 4mo ago2026-02-12 | 2025-12-31 | View filing |
| 13F-HR | Institutional holdings | 7mo ago2025-11-13 | 2025-09-30 | View filing |
| 13F-HR | Institutional holdings | 11mo ago2025-08-11 | 2025-06-30 | View filing |
| 13F-HR | Institutional holdings | 1y ago2025-05-12 | 2025-03-31 | View filing |
| 13F-HR | Institutional holdings | 1y ago2025-02-12 | 2024-12-31 | View filing |
| 13F-HR | Institutional holdings | 1y ago2024-11-12 | 2024-09-30 | View filing |
| 13F-HR | Institutional holdings | 1y ago2024-08-08 | 2024-06-30 | View filing |
| 13F-HR | Institutional holdings | 2y ago2024-05-09 | 2024-03-31 | View filing |
| 13F-HR | Institutional holdings | 2y ago2024-02-13 | 2023-12-31 | View filing |
| 13F-HR | Institutional holdings | 2y ago2023-11-09 | 2023-09-30 | View filing |
| 13F-HR | Institutional holdings | 2y ago2023-08-10 | 2023-06-30 | View filing |
| 13F-HR | Institutional holdings | 3y ago2023-05-11 | 2023-03-31 | View filing |
| 13F-HR | Institutional holdings | 3y ago2023-02-13 | 2022-12-31 | View filing |
| 13F-HR | Institutional holdings | 3y ago2022-11-09 | 2022-09-30 | View filing |
| 13F-HR | Institutional holdings | 3y ago2022-08-12 | 2022-06-30 | View filing |
| 13F-HR | Institutional holdings | 4y ago2022-05-12 | 2022-03-31 | View filing |
| 13F-HR | Institutional holdings | 4y ago2022-02-11 | 2021-12-31 | View filing |
| 13F-HR | Institutional holdings | 4y ago2021-11-12 | 2021-09-30 | View filing |
| 13F-HR | Institutional holdings | 4y ago2021-08-12 | 2021-06-30 | View filing |
| 13F-HR | Institutional holdings | 5y ago2021-05-14 | 2021-03-31 | View filing |
| 13F-HR | Institutional holdings | 5y ago2021-02-12 | 2020-12-31 | View filing |
| 13F-HR | Institutional holdings | 10y ago2016-02-16 | 2015-12-31 | View filing |
| 13F-HR | Institutional holdings | 10y ago2015-11-12 | 2015-09-30 | View filing |
| 13F-HR | Institutional holdings | 10y ago2015-08-12 | 2015-06-30 | View filing |
| 13F-HR | Institutional holdings | 11y ago2015-05-14 | 2015-03-31 | View filing |
| 13F-HR | Institutional holdings | 11y ago2015-02-17 | 2014-12-31 | View filing |
| 13F-HR | Institutional holdings | 11y ago2014-11-13 | 2014-09-30 | View filing |
| 13F-HR | Institutional holdings | 11y ago2014-08-08 | 2014-06-30 | View filing |
| 13F-HR | Institutional holdings | 12y ago2014-05-12 | 2014-03-31 | View filing |
| 13F-HR | Institutional holdings | 12y ago2014-02-13 | 2013-12-31 | View filing |
| 13F-HR | Institutional holdings | 12y ago2013-11-13 | 2013-09-30 | View filing |
| 13F-HR | Institutional holdings | 12y ago2013-08-09 | 2013-06-30 | View filing |
| 13F-HR | Institutional holdings | 13y ago2013-05-14 | 2013-03-31 | View filing |
| 13F-HR | Institutional holdings | 13y ago2013-02-13 | 2012-12-31 | View filing |
| 13F-HR | Institutional holdings | 13y ago2012-11-14 | 2012-09-30 | View filing |
| 13F-HR | Institutional holdings | 13y ago2012-08-13 | 2012-06-30 | View filing |
| 13F-HR | Institutional holdings | 14y ago2012-05-14 | 2012-03-31 | View filing |
| 13F-HR | Institutional holdings | 14y ago2012-02-13 | 2011-12-31 | View filing |
| 13F-HR | Institutional holdings | 14y ago2011-11-14 | 2011-09-30 | View filing |
| 13F-HR | Institutional holdings | 14y ago2011-08-12 | 2011-06-30 | View filing |
| 13F-HR | Institutional holdings | 15y ago2011-05-13 | 2011-03-31 | View filing |
| 13F-HR | Institutional holdings | 15y ago2011-02-14 | 2010-12-31 | View filing |
| 13F-HR | Institutional holdings | 15y ago2010-11-12 | 2010-09-30 | View filing |
| 13F-HR | Institutional holdings | 15y ago2010-08-12 | 2010-06-30 | View filing |
| 13F-HR | Institutional holdings | 16y ago2010-05-12 | 2010-03-31 | View filing |
| 13F-HR | Institutional holdings | 16y ago2010-02-16 | 2009-12-31 | View filing |
| 13F-HR | Institutional holdings | 16y ago2009-11-13 | 2009-09-30 | View filing |
| 13F-HR | Institutional holdings | 16y ago2009-08-13 | 2009-06-30 | View filing |
| 13F-HR | Institutional holdings | 17y ago2008-08-13 | 2008-06-30 | View filing |