Funds · 13F filer · Hanover, NH

White Mountains Insurance Group Ltd

$393.6M in 2 U.S. stocks and ETFs at the end of June 30, 2026, as reported to the SEC.1

1y return+10.8%S&P 500 +20.9%
3y return+37.4%S&P 500 +68.5%
5y return−64.2%S&P 500 +74.5%

These returns are for its stock picks as disclosed on Form 13F: last quarter's holdings, valued at this quarter's prices. They miss trades within each quarter, short positions, options, bonds, cash and fees, so they aren't the returns its clients got.

$100 invested in its stock picks

Since December 31, 2020: $39 against $200 in the S&P 500.2

White Mountains Insurance Group LtdS&P 500 (SPY)
$22$100$20020202026

Top holdings

At the end of June 30, 2026. Change is in shares since the quarter before.2

StockValueShare of portfolioChange
MAXMediaalpha Inc$224.5M57.0%
SPYSpdr S&p 500 Etf Tr$169.1M43.0%

Best picks still held

How each current holding has done since the quarter it first appeared in its filings (up to six years back).

StockHeld sinceReturn sinceNow worth
SPYSpdr S&p 500 Etf TrDecember 31, 2025+9.5%$169.1M
MAXMediaalpha IncDecember 31, 2020−67.8%$224.5M

Quarter by quarter

QuarterIts picksS&P 500
June 30, 2026+25.6%+14.8%
March 31, 2026−25.4%−4.6%
December 31, 2025+13.8%+2.4%
September 30, 2025+3.9%+7.8%
June 30, 2025+15.1%+10.5%
March 31, 2025−11.0%−4.6%
December 31, 2024−21.5%+2.1%
September 30, 2024+22.4%+5.4%
June 30, 2024−25.7%+4.0%
March 31, 2024+57.2%+10.0%
December 31, 2023+21.4%+11.2%
September 30, 2023−11.1%−3.6%
June 30, 2023−8.1%+8.3%
March 31, 2023+21.6%+7.0%
December 31, 2022+12.1%+7.1%
September 30, 2022−11.2%−5.3%
June 30, 2022−40.5%−16.5%
March 31, 2022+7.2%−4.9%
December 31, 2021−17.3%+10.7%
September 30, 2021−55.6%+0.3%

Sources

Every number on this page points here. Each one links to the public record.

  1. 1
    CIK 776867
  2. 2
    SEC: 13F for the quarter ended June 30, 2026https://www.sec.gov/Archives/edgar/data/776867/000110465926094905/
    Filed August 12, 2026 · accession 0001104659-26-094905