Stocks/Funds/CIK 776867

WHITE MOUNTAINS INSURANCE GROUP LTD

long-term holderconcentrated
Quarterly 13F filings · Latest period 2026-03-31 · CIK 776867
Assets
$313M
+9.6% YoY
Holdings
2
Lifetime alpha vs market
-16.19% annual
Average hold time
4.4 yr
median 4.4 yr

Quarterly history

Cum return -25% vs S&P +52% · α -77% lifetimeAUM $313M · peak $802MFlow $118M (+45%)2015-122021-092022-092023-092024-092025-092026-03
AUM ($B)fundS&P 500(gap = α)/ Flow in/out

Behavior signals (lifetime)

Dip response
+0.50%
adds when stocks drop
when a holding falls −10%+
Middle response
+11.24%
steady accumulation
Rally response
-8.29%
trims into rallies
when a holding rises +10%+

Top positions · 2

Ticker$ value% portYoYHold time
MAXMediaAlpha, Inc.$166M53.0%+0.6%5.5 yr
SPYState Street SPDR S&P 50$147M47.0%+17.6%3.3 yr

Portfolio composition (YoY)

Industry mix
Internet Content & Information53.0%-4.7pp$166M
Asset Management47.0%+4.7pp$147M
Country
US100.0%+0.0pp
Top 5: 100.0% · Top 10: 100.0% · Top 25: 100.0%

Winners

TickerPrev $PnLYoY %
SPY$121M+0.02B17.6%
MAX$165M+0.00B0.6%

Losers

TickerPrev $PnLYoY %

Top buys this quarter · 1

SPY State Street SPDR S&P 500 ETF +$118M

Top sells this quarter · 0

No sells this quarter

Quarterly history (TTM returns)

PeriodAUM# PosReturn (1yr)SPY (1yr)Alpha (1yr)Flow
2026-03-31$313M2+2.66%+17.59%-14.93%+0.12B
2025-12-31$262M2+22.64%+17.72%+4.92%+0.02B
2025-09-30$203M1-17.94%+17.52%-35.46%-0.00B
2025-06-30$196M1-3.08%+14.94%-18.02%-0.13B
2025-03-31$286M2-36.32%+8.30%-44.63%-0.09B
2024-12-31$426M2+12.74%+24.89%-12.15%+0.00B
2024-09-30$543M2+75.13%+36.04%+39.09%-0.00B
2024-06-30$444M2+26.84%+24.49%+2.35%-0.01B
2024-03-31$617M2+56.78%+29.62%+27.16%-0.00B
2023-12-31$393M2+21.56%+26.18%-4.61%-0.14B
2023-09-30$441M2+12.07%+21.57%-9.50%-0.01B
2023-06-30$508M2+12.93%+19.42%-6.49%-0.05B
2023-03-31$611M2-26.75%-7.82%-18.93%-0.00B
2022-12-31$502M2+12.30%+7.56%+4.74%+0.28B
2022-09-30$195M2-10.40%-4.93%-5.47%+0.05B
2022-06-30$167M1-40.48%-16.11%-24.37%+0.00B