White Mountains Insurance Group Ltd.
In its 13F for Q1 2026 (holdings as of March 31, 2026, filed May 12, 2026), White Mountains Insurance Group Ltd. reported 2 stock positions worth $313.4 million. Its top holding was Mediaalpha Class A (MAX) at 53.0% of the portfolio, followed by SS SPDR S&P 500 ETF Trust-US (SPY, 47.0%). Compared with Q4 2025, it added to 1. The biggest buy was SS SPDR S&P 500 ETF Trust-US (SPY, shares +403%).
- Most Recent 13F
- Q2 2026
- Location
- Hanover, NH
- CIK
- 0000776867
- Portfolio Value
- $313.4M (Q1 2026)
- SEC Filing
- 0001104659-26-059351 ↗ filed May 12, 2026
Holdings Value
Holdings 2 stocks · $313.4M
Portfolio Sells Q4 2025 → Q1 2026
| None this quarter. | |||
Portfolio Buys Q4 2025 → Q1 2026
| SPY SS SPDR S&P 500 ETF Trust-US | Add +403.3% | 47.01% | +35.29 |