White Mountains Insurance Group
WTM · NYSE
$2,213.61+$46.49 (+2.15%)TodayMarket closed ·
Prev close $2,167.12
Who owns WTM
Largest institutional holders, from their latest 13F filings
The 10 largest institutions hold 42.2% of WTM’s shares.
- Dimensional Fund Advisors, L.P.6.4%
- Neuberger Berman, LLC4.8%
- River Road Asset Management, LLC4.7%
- Vanguard Portfolio Management, LLC4.5%
- Next 6 largest institutions21.8%
- All other shareholders57.8%
| Holder | Shares | % of shares |
|---|---|---|
| Dimensional Fund Advisors, L.P. | 158.95K | 6.41% |
| Neuberger Berman, LLC | 119.14K | 4.80% |
| River Road Asset Management, LLC | 115.88K | 4.67% |
| Vanguard Portfolio Management, LLC | 111.97K | 4.51% |
| Vanguard Capital Management, LLC | 107.48K | 4.33% |
| Fuller & Thaler Asset Management Inc. | 101.89K | 4.11% |
| BlackRock Institutional Trust Company, N.A. | 99.62K | 4.02% |
| Cooke & Bieler, L.P. | 85.12K | 3.43% |
| Wallace Capital Management Inc. | 80.07K | 3.23% |
| Fiduciary Management, Inc. | 66.55K | 2.68% |
Largest mutual fund holders
| Holder | Shares | % of shares |
|---|---|---|
| Undiscovered Managers Behavioral Value Fund | 81.07K | 3.27% |
| Vanguard Total Stock Market Index Fund | 74.84K | 3.02% |
| Neuberger Genesis Fund | 68.18K | 2.75% |
| Vanguard Small-Cap Index Fund | 54.10K | 2.18% |
| Vanguard Selected Value Fund | 34.93K | 1.41% |
Insider trades
Form 4 filings by officers, directors and large holders
Insiders made no open-market buys or sales of WTM in the last 6 months.
| Insider | Type | Shares | Value |
|---|---|---|---|
| Tanner David Allen | Gift | 2 | — |
| Klar Stephen | Award | 113 | — |
| Chu John | Award | 135 | — |
| Dillon Margaret | Award | 135 | — |
| Gelston Philip A | Award | 135 | — |
| SHANK SUZANNE F. | Award | 135 | — |
| Carlson Peter M | Award | 135 | — |
| CAMPBELL REID TARLTON | Award | 135 | — |
| Tanner David Allen | Award | 135 | — |
| CHOKSI MARY C | Award | 135 | — |
Short interest
Settled Sep 30, 2026
- Shares short
- 139.65K
- Days to cover
- 7.43
- % of shares outstanding
- 5.63%
- Average daily volume
- 18.80K
- Change since last report
- +3.1%
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