WHITE MOUNTAINS INSURANCE GROUP LTD - WTM

All tracked SEC files for this issuer. Showing up to 200 latest records.
Need parsed ownership details (13D/13G with shares/percent)? Open ownership details
Form 4 = insider transactions report. Form 144 = notice of proposed sale (not a completed trade confirmation).

Files summary

Total files loaded: 28
Latest filed: Apr 01, 2026
Form Count
4 17
8-K 6
SCHEDULE 13G/A 3
SCHEDULE 13G 1
4/A 1

Latest files

Filed Form Report period Accession SEC
Apr 01, 2026 8-K Apr 01, 2026 0001628280-26-022818 View
Mar 27, 2026 SCHEDULE 13G/A 0000102909-26-002687 View
Mar 20, 2026 4 Mar 19, 2026 0000776867-26-000025 View
Mar 05, 2026 4 Mar 04, 2026 0000776867-26-000023 View
Feb 27, 2026 4 Feb 25, 2026 0000776867-26-000017 View
Feb 27, 2026 4 Feb 25, 2026 0000776867-26-000018 View
Feb 27, 2026 4 Feb 25, 2026 0000776867-26-000019 View
Feb 27, 2026 4 Feb 25, 2026 0000776867-26-000020 View
Feb 27, 2026 4 Feb 25, 2026 0000776867-26-000021 View
Feb 26, 2026 8-K Feb 26, 2026 0001628280-26-012417 View
Feb 12, 2026 SCHEDULE 13G/A 0000895421-26-000047 View
Feb 06, 2026 8-K Feb 06, 2026 0001628280-26-005947 View
Feb 05, 2026 SCHEDULE 13G 0001465109-26-000005 View
Jan 07, 2026 8-K Jan 07, 2026 0001628280-26-001102 View
Jan 05, 2026 4 Jan 01, 2026 0000776867-26-000010 View
Jan 02, 2026 4 Jan 01, 2026 0000776867-26-000006 View
Jan 02, 2026 4 Jan 01, 2026 0000776867-26-000007 View
Jan 02, 2026 4 Jan 01, 2026 0000776867-26-000009 View
Dec 23, 2025 4 Dec 23, 2025 0000776867-25-000034 View
Dec 22, 2025 4 Dec 19, 2025 0000776867-25-000029 View
Dec 22, 2025 4 Dec 19, 2025 0000776867-25-000030 View
Dec 22, 2025 4/A Dec 19, 2025 0000776867-25-000032 View
Dec 16, 2025 4 Dec 16, 2025 0000776867-25-000025 View
Dec 08, 2025 8-K Dec 05, 2025 0001628280-25-055702 View
Nov 26, 2025 4 Nov 25, 2025 0000776867-25-000021 View
Nov 10, 2025 4 Nov 10, 2025 0001318960-25-000008 View
Nov 07, 2025 SCHEDULE 13G/A 0000895421-25-000548 View
Nov 06, 2025 8-K Nov 06, 2025 0001628280-25-049888 View