WHITE MOUNTAINS INSURANCE GROUP LTD — 13F Holdings & Portfolio
CIK 776867 · latest 13F-HR filed 2026-08-12
WHITE MOUNTAINS INSURANCE GROUP LTD manages $393.6M in 13F-reported U.S. long-equity assets across 2 reported positions as of its 2026-06-30 13F-HR filing. Its largest disclosed positions are MAX (57.03%), SPY (42.97%). Quarter over quarter (versus its 2026-03-31 filing) the fund opened 0 new positions, exited 0, added to 2, and trimmed 0.
AUM is the long-equity portion reported on Form 13F-HR. Excludes short positions, cash, foreign holdings, and non-13F assets. For informational purposes only — not investment advice.
SUITE 3B
HANOVER, NH 03755
$393.6M
Long-equity book
2
Distinct positions
2026-06-30
Filed 2026-08-12
+0 / −0 / ↑2 / ↓0
vs 2026-03-31
| Name | Title / Status | Ownership | Type |
|---|
Top Adds (vs prior quarter)
- MEDIAALPHA INC$58.4M +35.2%
- SPDR S&P 500 ETF TR$21.8M +14.8%
Rows tagged Call or Put are options positions, not stock. Per SEC Form 13F-HR, Value shows the notional value of the underlying (shares covered × underlying price), not the option premium. Shares is the number of underlying shares covered (divide by 100 for contract count).
| Period | Filed | AUM | Holdings | Accession |
|---|---|---|---|---|
| 2026-06-30 | 2026-08-12 | $393.6M | 2 | 0001104659-26-094905 |
| 2026-03-31 | 2026-05-12 | $313.4M | 2 | 0001104659-26-059351 |
| 2025-12-31 | 2026-02-12 | $261.9M | 2 | 0001104659-26-014432 |
| 2025-09-30 | 2025-11-13 | $203.2M | 1 | 0001104659-25-110906 |
| 2021-09-30 | 2021-11-12 | $316.4K | 1 | 0001104659-21-137569 |
| 2021-06-30 | 2021-08-12 | $713.2K | 1 | 0001104659-21-104158 |