Company · CIK 0000776867 · SIC 6331 — Fire, Marine & Casualty Insurance · NYSE
WHITE MOUNTAINS INSURANCE GROUP LTD · WTM
Insider activity reported against this company. All insider holders · Files at: OB, SYA. On EDGAR ↗
Reported at this company — common stock
| Trade | Reported (ET) | Insider | Shares | Avg price | Total | Owned after | Δ stake | Flags |
|---|---|---|---|---|---|---|---|---|
| Aug 31, 2026 GForm 4 → | Aug 31, 5:04 pm EDT | David Allen TannerDirector | 2 | — | — | 2,012 | — | |
| Aug 26, 2026 AForm 4 → | Aug 27, 3:46 pm EDT | Stephen KlarDirector | 113 | — | — | 113 | — |
Reported at this company — derivatives (options, RSUs, warrants)
No reported derivative activity in this period.
Filed by this entity as an insider elsewhere — common stock
No reported common-stock activity in this period.
Filed by this entity as an insider elsewhere — derivatives (options, RSUs, warrants)
No reported derivative activity in this period.