White Mountains Insurance Group, Ltd.
White Mountains Insurance Group, Ltd. is a registered legal entity registered in Bermuda under 27225, and its current status with Bermuda Monetary Authority / Registrar of Companies is active. The company was incorporated on 25 October 1999 and lists its registered address as Hamilton, Bermuda. 5 shareholders are on record for White Mountains Insurance Group, Ltd., including at least one natural person recorded as a direct holder; the filing carries no beneficial-ownership flag, so that holder is noted here as a recorded shareholder rather than a confirmed ultimate beneficial owner (UBO). This profile is sourced directly from Bermuda Monetary Authority / Registrar of Companies and was last updated on 25 September 2026.
- Company fundamentals
- Corporate linkage & group structures
- Digitized company financials
- Firmographics — websites, social profiles, revenue and employee estimates
Shareholders
5
Shareholders of White Mountains Insurance Group, Ltd.
Five shareholders are currently on record for White Mountains Insurance Group, Ltd., held on the register of members, filed under the Companies Act 1981. The largest of these is Morgan Stanley, holding 10.8% — the largest recorded stake — followed by Boston Partners at 6.3%; the remaining 3 shareholders shown hold smaller stakes. 3 shareholders shown are companies, so the ownership chain continues above this level for those holdings; the other 2 are recorded as direct individual holders, though the record carries no UBO/PSC flag confirming beneficial-owner status.
Data availability
The register reports 20 shareholders in total, though only the top 5 by holding are shown in this view.
| Shareholder | Type | Holding | Source Document |
|---|---|---|---|
| Morgan Stanley | 10.8% | Bermuda Monetary Authority / Registrar of Companies | |
| Boston Partners | 6.3% | Bermuda Monetary Authority / Registrar of Companies | |
| Blackrock Inc. | 6% | Bermuda Monetary Authority / Registrar of Companies | |
| DFA U.S. Small Cap Value Series | 2.3% | Bermuda Monetary Authority / Registrar of Companies | |
| Vanguard Extended Market Index Fund | 1.9% | Bermuda Monetary Authority / Registrar of Companies |
Officers
10
Directors and officers of White Mountains Insurance Group, Ltd.
The Ceo & Director of White Mountains Insurance Group, Ltd. currently on record is George Rountree; 10 officers are currently on record for White Mountains Insurance Group, Ltd., filed with Bermuda Monetary Authority / Registrar of Companies. Management authority at White Mountains Insurance Group, Ltd. sits with these individuals, not with shareholders, who are covered separately and hold ownership rather than control. The source filing doesn't specify representation authority — whether officers can act individually or must sign jointly to bind the company — so that detail isn't available here.
Group Structure
Group structure of White Mountains Insurance Group, Ltd.
White Mountains Insurance Group, Ltd. has no recorded parent company — it sits at the top of its own group structure, with 32 subsidiaries recorded beneath it across 4 jurisdictions. Each of these downward relationships is derived rather than filed: resolved by matching entities across the registry network, not stated directly in a single document.
- Ide8 RE Cell 2, Inc. (United States)
- Attorneys & Professionals Insurance Services, Inc. (United States)
- Distinguished Specialty Insurance Brokerage LLC (United States)
- Embrace Pet Management LLC (United States)
- Ark Insurance Holdings Limited (Bermuda)
- Hg Services Ltd. (Bermuda)
- WM Paget (Bermuda) Ltd. (Bermuda)
- Ark Underwriting, Inc. (United States)
- Hg Re Ltd. (Bermuda)
- WTM (BARBADOS) INTERNATIONAL SRL (Barbados)
Data availability
Those 32 subsidiaries span Bermuda, United States, Barbados, Israel jurisdictions, though this list should not be read as complete — subsidiaries only become visible here where shareholder data has actually been filed with a register, so holdings in jurisdictions without that filing simply won't appear. Five of the 32 go a level deeper still, with their own further subsidiaries recorded beneath them — additional ownership layers this view doesn't expand.
White Mountains Insurance Group, Ltd.
Bermuda
Get complete shareholder and officer records, ultimate beneficial owner resolution, and ongoing ownership monitoring.
Frequently Asked Questions
Who owns White Mountains Insurance Group, Ltd.?
Five shareholders are currently on record for White Mountains Insurance Group, Ltd., held on the register of members, filed under the Companies Act 1981. The largest of these is Morgan Stanley, holding 10.8% — the largest recorded stake — followed by Boston Partners at 6.3%; the remaining 3 shareholders shown hold smaller stakes. 3 shareholders shown are companies, so the ownership chain continues above this level for those holdings; the other 2 are recorded as direct individual holders, though the record carries no UBO/PSC flag confirming beneficial-owner status.
Who is White Mountains Insurance Group, Ltd.'s UBO (Ultimate Beneficial Owner)?
At least one shareholder recorded for White Mountains Insurance Group, Ltd. is a natural person. The record carries no dedicated UBO/PSC flag, so that holder is stated here as a recorded shareholder rather than a confirmed Ultimate Beneficial Owner (UBO).
How many shareholders does White Mountains Insurance Group, Ltd. have on record?
5 shareholders are shown on record for White Mountains Insurance Group, Ltd.. The register reports 20 in total; only the top 5 by holding are shown here.
What is White Mountains Insurance Group, Ltd.'s company registration number?
White Mountains Insurance Group, Ltd.'s registration number is 27225, filed with Bermuda Monetary Authority / Registrar of Companies in Bermuda. Its current status on the register is active.
Is White Mountains Insurance Group, Ltd. still an active company?
White Mountains Insurance Group, Ltd.'s status on Bermuda Monetary Authority / Registrar of Companies is listed as active.
When was White Mountains Insurance Group, Ltd. incorporated?
White Mountains Insurance Group, Ltd. was incorporated on 25 October 1999, according to Bermuda Monetary Authority / Registrar of Companies.
What is White Mountains Insurance Group, Ltd.'s registered address?
The registered address on file for White Mountains Insurance Group, Ltd. is Hamilton, Bermuda.
Who are the officers/directors of White Mountains Insurance Group, Ltd.?
The Ceo & Director of White Mountains Insurance Group, Ltd. currently on record is George Rountree; 10 officers are currently on record for White Mountains Insurance Group, Ltd., filed with Bermuda Monetary Authority / Registrar of Companies. Management authority at White Mountains Insurance Group, Ltd. sits with these individuals, not with shareholders, who are covered separately and hold ownership rather than control.
Does White Mountains Insurance Group, Ltd. have a parent company or subsidiaries?
White Mountains Insurance Group, Ltd. has no recorded parent company — it sits at the top of its own group structure, with 32 subsidiaries recorded beneath it across 4 jurisdictions. Those 32 subsidiaries span Bermuda, United States, Barbados, Israel jurisdictions, though this list should not be read as complete — subsidiaries only become visible here where shareholder data has actually been filed with a register, so holdings in jurisdictions without that filing simply won't appear. Five of the 32 go a level deeper still, with their own further subsidiaries recorded beneath them — additional ownership layers this view doesn't expand.
Can Zavia monitor changes to White Mountains Insurance Group, Ltd.'s ownership over time?
This profile reflects a point-in-time snapshot from Bermuda Monetary Authority / Registrar of Companies. Zavia's monitoring API can track changes to White Mountains Insurance Group, Ltd.'s registered shareholders, officers, and group structure going forward, flagging updates as they're filed rather than requiring a manual recheck.
Can I access White Mountains Insurance Group, Ltd.'s data through an API?
Yes. Zavia's API connects directly to official government ownership registries across 195 countries and territories, including Bermuda, so records like White Mountains Insurance Group, Ltd.'s registration, shareholder, UBO, and group-structure data can be queried programmatically instead of viewed one page at a time.
Where does this company information come from, and how current is it?
This record is sourced directly from Bermuda Monetary Authority / Registrar of Companies and was last synced on 25 September 2026.