George Manning Rountree - 19 Dec 2025 Form 4 Insider Report for WHITE MOUNTAINS INSURANCE GROUP LTD (WTM)

Reporting relationship: Chief Executive Officer, Director
Issuer ticker: WTM
Reported as of: 19 Dec 2025
Net transaction value: -$10,250,000
SEC form: 4
Accepted by SEC: 22 Dec 2025, 10:13:58 UTC
Prior SEC filing: 28 Feb 2025
Source filing: View source filing
Reporting owner signature: Wesley C. Bell, by Power of Attorney

Key filing fact

George Manning Rountree filed Form 4 for WHITE MOUNTAINS INSURANCE GROUP LTD (WTM) on 22 Dec 2025.

Key facts

This page summarizes George Manning Rountree's Form 4 filing for WHITE MOUNTAINS INSURANCE GROUP LTD (WTM).
1 reported transaction and 0 derivative rows are listed below.
Accepted by SEC: 22 Dec 2025, 10:13.

Change

Previous filing in this sequence was filed on 28 Feb 2025.
Current net transaction value: -$10,250,000.

Research use

This tells you what this filing adds before you inspect full transaction and derivative tables.
You can trace every row back to the original SEC filing document.

Evidence

Filed on Form 4

Ownership activity is grounded in SEC Form 4 disclosures.

View source filing

Reporting Owners (1)

CIK 0001457475 Primary reporting owner

Rountree George Manning

Relationship: Chief Executive Officer, Director
Address: C/O WHITE MOUNTAINS INSURANCE GROUP, LTD, 23 SOUTH MAIN STREET, SUITE 3B, HANOVER
Signature: Wesley C. Bell, by Power of Attorney
Signature date: 22 Dec 2025

Reported non-derivative transactions

Shares, units, or other non-derivative securities reported in this filing.

WTM transaction

Common Shares

Sale

Transaction value: $10,250,000
Shares: -5,000
Change %: -27%
Price: $2050.00
Shares after: 13,809
Date: 19 Dec 2025
Ownership: Direct

WTM holding

Common Shares (restricted)

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 5,425
Date: 19 Dec 2025
Ownership: Direct

WTM holding

Common Shares

No transaction description listed

Transaction value
Shares
Change %
Price
Shares after: 122
Date: 19 Dec 2025
Ownership: by 401(k)
Footnotes: F1

^* marks a reported price that did not pass the local price check.

Additional SEC filing notes

Filing notes and footnotes

Explanation of responses 1 footnote

Footnote F1

Reflects accumulation of 2 Common Shares in Reporting Person's Company retirement account since his last filed report. The information in this report is based on a plan report dated as of December 20, 2025.