WHITE MOUNTAINS INSURANCE GROUP LTD
Company Information
Industry
Fire, Marine & Casualty Insurance
SIC Code
6331
Entity Type
operating
SEC Category
Large accelerated filer
State of Incorporation
Bermuda
Business Address
23 SOUTH MAIN STREET, HANOVER, NH, 03755
Mailing Address
23 SOUTH MAIN STREET, HANOVER, NH, 03755
Phone
603 640 2200
Fiscal Year End
1231
EIN
942708455
Financial Overview
FY2025
Recent SEC Filings
| Form Type | Date Filed | Document |
|---|---|---|
| SCHEDULE 13G/A Passive ownership amendment | March 27, 2026 | View on SEC |
| 4 Insider stock transaction report | March 20, 2026 | View on SEC |
| 4 Insider stock transaction report | March 5, 2026 | View on SEC |
| 10-K Annual financial report | February 27, 2026 | View on SEC |
| 4 Insider stock transaction report | February 27, 2026 | View on SEC |
| 4 Insider stock transaction report | February 27, 2026 | View on SEC |
| 4 Insider stock transaction report | February 27, 2026 | View on SEC |
| 4 Insider stock transaction report | February 27, 2026 | View on SEC |
| 4 Insider stock transaction report | February 27, 2026 | View on SEC |
| 8-K Current report of material events | February 26, 2026 | View on SEC |
Annual Reports
10-K
February 27, 2026
- Manages a diverse portfolio across insurance, reinsurance, and investment management businesses.
- Operates core P&C platforms (Ark), municipal bond insurance (HG Global BAM), and invests in asset management firms (Kudu).
Material Events
8-K
Strategy Change
December 8, 2025
High Impact
- WHITE MOUNTAINS INSURANCE GROUP LTD completed the sale of a 77.3% controlling interest in WM Pierce Holdings, Inc. (Bamboo Group).
- The sale was made to investment funds advised by CVC Capital Partners for $848 million in cash.
Insider Trading
STRONG SELL
3 insiders
4 recent transactions
View Full Insider Trading Profile
Related Companies
Companies in the same industry (SIC: 6331)
UNIVERSAL INSURANCE HOLDINGS, INC.
UVE
Fire, Marine & Casualty Insurance
EVEREST REINSURANCE HOLDINGS INC
Fire, Marine & Casualty Insurance
OXBRIDGE RE HOLDINGS Ltd
OXBR
Fire, Marine & Casualty Insurance
ASPEN INSURANCE HOLDINGS LTD
AHL
Fire, Marine & Casualty Insurance
KINGSWAY FINANCIAL SERVICES INC
KFS
Fire, Marine & Casualty Insurance
Investor Resources
Learn more about SEC filings and how to research public companies.
What is the SEC?
A plain English guide to the Securities and Exchange Commission
Understanding SEC Filings & CIK
How to navigate SEC filings and Central Index Keys
10-K Annual Reports Explained
Everything you need to know about annual reports
S-1 & F-1 IPO Filings
Understanding IPO registration statements
SEC EDGAR Database Guide
How to use the SEC's free filing database
Important Disclaimer
This AI-generated analysis is for informational purposes only and does not constitute financial or investment advice. Always consult with qualified professionals and conduct your own research before making investment decisions.