White Mountains Insurance Gp
Held by 2 superinvestors (WTM).
Educational data only — not investment advice. 13F positions are self-reported and can lag up to 45 days.
Ownership · 13F consensus
Who's buying it
Institutional ownership aggregated across funds — consensus strength and this quarter's moves. Describes actions, not advice.
2 superinvestors hold it · $42.4M combined
Largest holder Mason Hawkins
Held by 2 superinvestors of White Mountains Insurance Gp (WTM); this quarter 1 opened, 1 trimmed (as of 2026-03-31).
13F positions are self-reported and can lag up to 45 days. Informational only — not investment advice.
Superinvestors Holding This Security
- Value$41.4MWeight (prev→now)2.9% → 2.0% ▼
- Value$909,541Weight (prev→now)New · 0.0%
Ownership overview
White Mountains Insurance Gp (WTM) is held by 2 of the superinvestors tracked on Compounder, with a combined $42.4M in reported 13F value. The largest position belongs to Mason Hawkins, where it makes up 2.0% of the portfolio.
Other notable holders by value include Ray Dalio (0.0% of its book).
Over the latest quarter, 1 of the tracked filers opened a new position in WTM, 0 added to existing ones, 1 trimmed, and 0 sold out entirely.
Holder counts and values reflect the most recent SEC Form 13F filings, through the quarter ended 2026-03-31. Source: SEC EDGAR. A 13F shows only long US-listed positions and can lag the real portfolio by up to 45 days, so this is disclosed long ownership, not a complete picture.
Holders over time
Superinvestors holding this security over the last 8 quarters: 2 → 2.
Early quarters may understate holder counts due to data backfill — read the slope with care.
Sources· SEC EDGAR 13F as of 2026-05-15
Related
Stay Updated
Curated 13F moves and valuation insights, straight to your inbox.