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White Mountains Insurance Group Ltd

Hanover, NH 4 processed 13Fs on this site, 2025 Q3 to 2026 Q2

  • $394M
  • 2 holdings
  • 2026 Q2
  • +25.9% QoQ
  • Top 5 100.0%

Portfolio

2026 Q2, filed 8/12/2026, 2 holdings

Top 5 100.0%, top 10 100.0%

  1. MAX, Mediaalpha 57.0%
  2. SPY, SPDR S&P 500 ETF Trust 43.0%

AUM over time

2026 Q2 $394M +25.9% QoQ
2025 Q3: $203M 2025 Q3: $203M
Q3 2025
2025 Q4: $262M, +29.1% QoQ 2025 Q4: $262M, +29.1% QoQ
Q4
2026 Q1: $313M, +19.5% QoQ 2026 Q1: $313M, +19.5% QoQ
Q1 2026
2026 Q2: $394M, +25.9% QoQ 2026 Q2: $394M, +25.9% QoQ
Q2

Book

2025 Q3, filed 13 Nov, long equity only

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MAX, Mediaalpha 100.00% Hold 17,856,614 $11.38 $203M

* Reported price is value ÷ shares from the 13F as of period end, not a live market quote. Weight % is each long-equity position ÷ full 13F AUM, so rows may not sum to 100% when the filing includes options or other non-equity (excluded from this table). Click a column header to sort, or New, Hold, Add or Reduce to bring those moves to the top.

Filings history

4 periods, with AUM normalized

Newest 13Fs
Period Holds AUM QoQ Form Filed Filing ID
2026 Q2 2 $394M +25.9% 13F-HR 8/12/2026 000110465926094905
2026 Q1 2 $313M +19.5% 13F-HR 5/12/2026 000110465926059351
2025 Q4 2 $262M +29.1% 13F-HR 2/12/2026 000110465926014432
2025 Q3 1 $203M — 13F-HR 11/13/2025 000110465925110906

About

White Mountains Insurance Group Ltd

4 processed 13Fs on this site, 2025 Q3 to 2026 Q2

SEC filing name
WHITE MOUNTAINS INSURANCE GROUP LTD
Location
Hanover, NH
All SEC filings
View on sec.gov

Further reading

As an Amazon Associate, FollowTheFilings earns from qualifying purchases.

  • The Essays of Warren Buffett, 8th Ed., Warren Buffett, Lawrence A. Cunningham View on Amazon
  • One Up On Wall Street (Lynch), Peter Lynch View on Amazon

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