WHITE MOUNTAINS INSURANCE GROUP LTD (WTM) Insider Trading & SEC Filings

Updated Jul 16, 2026 · Last SEC filing 2026-05-22

WHITE MOUNTAINS INSURANCE GROUP LTD (WTM) has filed 9 SEC Form 4 insider transactions in the last 90 days, with the most recent on 2026-05-22. 4 Form 8-K material event filings were reported by WTM in the last 90 days. InsiderAlpha tracks every WTM SEC filing — Form 4, Form 144, and 8-K — in real time, including Rule 10b5-1 plan detection.

About WHITE MOUNTAINS INSURANCE GROUP LTD (WTM)

SEC CIK0000776867

90-Day SEC Filing Activity

Form 4 filings (90d)9
Form 8-K filings (90d)4
Latest Form 4 filing2026-05-22

Recent WTM Insider Transactions (Form 4)

DateInsiderRoleTransactionSharesPriceValueFiling
CHOKSI MARY CDirectorA — Grant or award135$0.00—SEC
Chu JohnDirectorA — Grant or award135$0.00—SEC
CAMPBELL REID TARLTONDirectorA — Grant or award135$0.00—SEC
Carlson Peter MDirectorA — Grant or award135$0.00—SEC
Dillon MargaretDirectorA — Grant or award135$0.00—SEC
Gelston Philip ADirectorA — Grant or award135$0.00—SEC
Hicks Weston MDirectorA — Grant or award190$0.00—SEC
SHANK SUZANNE F.DirectorA — Grant or award135$0.00—SEC
Tanner David AllenDirectorA — Grant or award135$0.00—SEC
SEELIG ROBERT LAWRENCEEVP & General CounselG — Bona-fide gift50$0.00—SEC
Tanner David AllenDirectorG — Bona-fide gift225$0.00—SEC
Hildreth MichaelaMD & Chief Accounting OfficerA — Grant or award600$0.00—SEC
Caffrey Liam PChief Executive OfficerA — Grant or award1.5K$0.00—SEC
Harrison Giles EPresidentA — Grant or award775$0.00—SEC
Papamichael Michael AChief Financial OfficerA — Grant or award500$0.00—SEC

All transactions sourced from SEC EDGAR Form 4 filings for WHITE MOUNTAINS INSURANCE GROUP LTD (WTM). Updated in real time as new filings are submitted to the SEC.

Most-Active WTM Insiders — Last 90 Days

InsiderForm 4 filingsTotal transaction value
CHOKSI MARY C1—
Hicks Weston M1—
Dillon Margaret1—
Tanner David Allen1—
CAMPBELL REID TARLTON1—

Recent WTM Form 8-K Material Events

Recent Insider Filings

Form 4 Transaction Code Reference

SEC Form 4 transactions are reported with a one-letter code indicating the type of transaction. Common codes you'll see in WTM insider filings:

POpen-market purchase by the insider
SOpen-market sale by the insider
AGrant, award, or other acquisition from the issuer
MExercise or conversion of derivative security (e.g. options)
FPayment of exercise price or tax liability via share withholding
GBona-fide gift of securities
DDisposition to the issuer (e.g. share buyback participation)
JOther acquisition or disposition
XExercise of in-the-money or at-the-money derivative security
CConversion of derivative security
VTransaction voluntarily reported earlier than required

WTM Insider Trading — FAQ

What is the latest insider trade for WTM?
WHITE MOUNTAINS INSURANCE GROUP LTD (WTM) had 9 insider filings in the last 90 days, with the most recent on 2026-05-22. InsiderAlpha tracks every Form 4, 10-K, 10-Q, and 8-K filing in real time.
How many insiders are buying WTM stock?
0 insider purchases of WTM were filed in the last 90 days.
How many insiders are selling WTM stock?
0 insider sales of WTM were filed in the last 90 days.
Where can I see WTM SEC filings (Form 4, 10-K, 10-Q, 8-K)?
InsiderAlpha aggregates every WTM SEC filing — Form 4 insider transactions, 10-K and 10-Q quarterly reports, and 8-K material event disclosures — in one timeline.

Learn More

Open the live WTM dashboard on InsiderAlpha for real-time alerts, charting, and full historical filing search.