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: 29
Latest filed: Jun 05, 2026
Form Count
4 16
8-K 7
SCHEDULE 13G/A 3
SCHEDULE 13G 2
SCHEDULE 13D/A 1

Latest files

Filed Form Report period Accession SEC
Jun 05, 2026 8-K Jun 05, 2026 0001628280-26-041051 View
May 22, 2026 4 May 21, 2026 0000776867-26-000036 View
May 22, 2026 4 May 21, 2026 0000776867-26-000037 View
May 22, 2026 4 May 21, 2026 0000776867-26-000038 View
May 22, 2026 4 May 21, 2026 0000776867-26-000040 View
May 22, 2026 4 May 21, 2026 0000776867-26-000041 View
May 22, 2026 4 May 21, 2026 0000776867-26-000042 View
May 22, 2026 4 May 21, 2026 0000776867-26-000043 View
May 22, 2026 4 May 21, 2026 0000776867-26-000044 View
May 22, 2026 4 May 21, 2026 0000776867-26-000045 View
May 21, 2026 8-K May 21, 2026 0001628280-26-037284 View
May 15, 2026 8-K May 14, 2026 0001628280-26-035349 View
May 07, 2026 SCHEDULE 13G/A 0001465109-26-000020 View
May 06, 2026 8-K May 06, 2026 0001628280-26-030930 View
May 01, 2026 SCHEDULE 13D/A 0000950157-26-000566 View
Apr 30, 2026 SCHEDULE 13G 0002100119-26-001212 View
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