WHITE MTNS INS GROUP LTD (WTM) Institutional Ownership Changes & 13F Activity
WHITE MTNS INS GROUP LTD (WTM). Institutional ownership data tracks hedge funds, asset managers, and other institutional investors based on recent SEC Form 13F filings (Q1 2026). This page analyzes institutional buying and selling activity, new holdings, and sold-out positions in the latest reporting period. Notable filers include T. Rowe Price Investment Management, Inc., Morgan Stanley, M&T Bank Corp, Boussard & Gavaudan Investment Management Llp, and Longleaf Partners.
| Institution | Type | Change in shares | Change Position % | Shares | Reported stock balance | Portfolio quarter | Filing date |
|---|---|---|---|---|---|---|---|
| Neuberger Berman Group Llc | Sell | -4,939 | -3.8% | 124,715 | $273.99M | Q1 2026 | Oct 27, 2026 |
| M&T Bank Corp | Sell | -18,387 | -99.1% | 162 | $355.91K | Q1 2026 | Sep 04, 2026 |
| Wells Fargo & Company/Mn | Sell | -359 | -3.9% | 8,782 | $19.29M | Q1 2026 | Jul 08, 2026 |
| Edgestream Partners, L.P. | Buy | +2,601 | +491.7% | 3,130 | $6.88M | Q1 2026 | May 18, 2026 |
| Amundi | Buy | +615 | — | 615 | $1.35M | Q1 2026 | May 18, 2026 |
| Bank Of America Corp | Sell | -448 | -1.6% | 28,358 | $62.30M | Q1 2026 | May 18, 2026 |
| California State Teachers Retirement System | Buy | +430 | +17.5% | 2,887 | $6.34M | Q1 2026 | May 18, 2026 |
| T. Rowe Price Investment Management, Inc. | Buy | +34,851 | +523.1% | 41,513 | $91.20M | Q1 2026 | May 15, 2026 |
| Morgan Stanley | Sell | -22,856 | -27.8% | 59,295 | $130.27M | Q1 2026 | May 15, 2026 |
| Boussard & Gavaudan Investment Management Llp | Buy | +13,975 | — | 13,975 | $30.97M | Q1 2026 | May 15, 2026 |
| Longleaf Partners | Sell | -12,788 | -40.4% | 18,864 | $41.44M | Q1 2026 | May 15, 2026 |
| Susquehanna International Group, Llp | Buy | +10,833 | +8206.8% | 10,965 | $24.09M | Q1 2026 | May 15, 2026 |
| Goldman Sachs Group Inc | Buy | +10,523 | +200.1% | 15,783 | $34.67M | Q1 2026 | May 15, 2026 |
| Select Equity Group, L.P. | Sell | -9,153 | -46.4% | 10,560 | $23.20M | Q1 2026 | May 15, 2026 |
| American Century Companies Inc | Buy | +7,413 | +828.3% | 8,308 | $18.25M | Q1 2026 | May 15, 2026 |
| Gendell Jeffrey L | Buy | +5,294 | +16.3% | 37,814 | $83.08M | Q1 2026 | May 15, 2026 |
| Victory Capital Management Inc | Buy | +4,849 | +77.0% | 11,145 | $24.49M | Q1 2026 | May 15, 2026 |
| Bradley Foster & Sargent Inc/Ct | Sell | -3,454 | -63.3% | 2,002 | $4.40M | Q1 2026 | May 15, 2026 |
| Aqr Capital Management Llc | Buy | +3,262 | +72.9% | 7,738 | $17.00M | Q1 2026 | May 15, 2026 |
| Marshall Wace, Llp | Buy | +2,780 | +253.2% | 3,878 | $8.52M | Q1 2026 | May 15, 2026 |
| Quantinno Capital Management Lp | Buy | +2,513 | +34.6% | 9,784 | $21.50M | Q1 2026 | May 15, 2026 |
| Gotham Asset Management, Llc | Buy | +2,331 | +34.7% | 9,047 | $19.88M | Q1 2026 | May 15, 2026 |
| Cerity Partners Llc | Sell | -1,676 | -47.3% | 1,867 | $4.10M | Q1 2026 | May 15, 2026 |
| London Co Of Virginia | Sell | -1,566 | -2.7% | 57,131 | $125.54M | Q1 2026 | May 15, 2026 |
| Wallace Capital Management Inc. | Sell | -1,552 | -1.9% | 78,795 | $173.11M | Q1 2026 | May 15, 2026 |
| State Street Corp | Sell | -1,505 | -3.0% | 49,158 | $108.00M | Q1 2026 | May 15, 2026 |
| Citadel Advisors Llc | Buy | +1,410 | +118.2% | 2,603 | $5.72M | Q1 2026 | May 15, 2026 |
| Dark Forest Capital Management Lp | Sell | -1,360 | -37.6% | 2,255 | $4.95M | Q1 2026 | May 15, 2026 |
| Empowered Funds, Llc | Buy | +1,195 | +1342.7% | 1,284 | $2.82M | Q1 2026 | May 15, 2026 |
| Tidal Investments Llc | Buy | +1,144 | +560.8% | 1,348 | $2.96M | Q1 2026 | May 15, 2026 |
Frequently asked questions about WTM activity
Which institutional owners are buying WTM?
Institutional owners buying WTM include investors who have either initiated new positions or increased their existing holdings based on recent SEC 13F filings. The activity table above highlights which funds added shares in the latest reporting periods and how their positions changed over time.
What does "buy" mean in WTM activity?
"Buy" means an investor increased their reported position in WTM compared to the prior reporting period. This reflects growing exposure to WHITE MTNS INS GROUP LTD (WTM) rather than necessarily a brand-new position (though new positions also appear as buys when prior quantity was zero).
Is institutional interest in WTM increasing?
Institutional interest in WTM can be assessed by comparing the number of tracked funds adding or increasing positions versus those trimming or exiting across the periods shown. A higher number of additions typically signals increasing participation among large filers, but it should be read alongside position sizes and the full table.
Related WTM Institutional Insights
- WTM Overview
- WTM 13F Institutional Holders
- WTM Superinvestors
- Financial Services Sector Institutional Ownership
- Financial Services Sector Portfolio Overlap
- Institutional Portfolio Overlap & Shared Holdings
- Most Bought Financial Services Stocks By Institutional Investors
- Most Sold Financial Services Stocks By Institutional Investors
- WTM Insider Trading & SEC Form 4 Activity
- WTM Articles
- Top Institutional Investor Stock Rankings