WHITE MTNS INS GROUP LTD (WTM) Institutional Ownership and Insiders Activity

WHITE MTNS INS GROUP LTD (WTM) is widely held by institutional investors, with 344 firms reporting positions valued at approximately $4.57B based on SEC Form 13F filings for the quarter ended June 30, 2026.

Dimensional Fund Advisors Lp is the largest disclosed holder, reporting approximately $329.58M in WTM holdings in its latest filing.

Recent insider activity includes 1 tracked Form 4 transaction over the last three months, reflecting ongoing executive and director trading activity.