White Mountains Insurance Group, Ltd. (WTM)
Financial Services
Insurance - Property & Casualty
2,098.80 $
+0.0%
vs. previous close
Closing price · As of: 3. Aug 2026
Who owns White Mountains Insurance Group, Ltd. (WTM)? This page shows the largest institutions and funds, the ownership structure and the latest insider transactions. 95.6% of the shares are freely tradable; institutional investors hold 94.0%.
Ownership Structure
Institutional ownership
Share of the stock held by institutional investors (funds, banks, insurers) according to regulatory filings.
94.0%
Insiders
Share of the stock held by the executives, founders and major shareholders of the company itself.
3.1%
Float
Share of stock freely tradable on the market — not locked up in the hands of founders, insiders, or major shareholders.
95.6%
Short % of float
Shares sold short as a percentage of the freely tradable float — high values signal many bets on falling prices.
5.8%
Shares Outstanding
Total number of shares issued. Price times share count gives market cap.
3Mio.
Largest Shareholders
Institutions
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| Dimensional Fund Advisors, Inc. | 6.32 | 156,618 | +0.0 | 03/31/2026 |
| Neuberger Berman Group LLC | 5.04 | 124,715 | -3.8 | 03/31/2026 |
| River Road Asset Management, LLC | 4.68 | 115,880 | -3.8 | 06/30/2026 |
| Vanguard Portfolio Management, LLC | 4.67 | 115,553 | +0.0 | 03/31/2026 |
| BlackRock Inc | 4.58 | 113,328 | +0.9 | 03/31/2026 |
| Vanguard Capital Management, LLC | 4.41 | 109,157 | +0.0 | 03/31/2026 |
| Cooke & Bieler LP | 4.23 | 104,857 | -1.6 | 03/31/2026 |
| Fuller & Thaler Asset Management Inc | 4.22 | 104,561 | -51.7 | 03/31/2026 |
Funds
| Name | Stake (%) | Shares | Change (%) | Date |
|---|---|---|---|---|
| FullerThaler Behavioral Small-Cap Value | 3.68 | 91,237 | -0.1 | 05/31/2026 |
| Undiscovered Managers Behavioral Val L | 3.45 | 85,474 | +0.0 | 05/31/2026 |
Largest reported positions according to regulatory filings; stake as a percentage of shares outstanding, change versus the previous filing. Source: fundamentals data.
Data as of: August 3, 2026 · Source: fundamental data & SEC filings (annual and quarterly reports, 10-K/10-Q)
Note: pure fact-based analysis, not investment advice and not a solicitation to buy or sell. All figures without guarantee.