MarketPeel
Insider Trading Intelligence
PG

Philip A. Gelston

WTM
DIRECTOR · WHITE MOUNTAINS INSURANCE GROUP LTD · CIK 0001733327
FILING MIX · LIFETIME88%/12%
BUYS
7
SELLS
1
TOTAL VALUE
$338.0K
COMPANIES
1
ACTIVE SINCE
May 2020
HOLDINGS NOW
1,703
AVG SELL PX
$2,048.51
TRADE KIND
SHOWING 8 / 8
Trades · vs SPY
Loading price series…
Performance · forward returns vs SPY
1 backtested trades · 8 horizons · 2 pendingHow are these numbers computed? →
Forward-return performance of every backtestable P/S trade by Philip A. Gelston, measured at 8 horizons from 7 days to 2 years. Deduped per economic event so co-filings count once. Excess return = trade return minus SPY return over the same window.
HORIZONTRADESWIN RATEINSIDER RETURNSPY RETURNMEAN EXCESSMEDIAN EXCESST-STAT
7d1+0.00%+2.23%+1.34%+0.89%+0.89%
14d1+0.00%+1.63%+1.20%+0.43%+0.43%
30d1+0.00%+0.81%+1.97%-1.16%-1.16%
60d1+0.00%+6.98%+0.42%+6.56%+6.56%
90d1+0.00%+7.55%-1.45%+9.00%+9.00%
180d1+100.00%-1.38%+9.26%-10.64%-10.64%
1y1(1 pending)
2y1(1 pending)
How to read this: Insider Returnis the average raw return of the filer's trades over the horizon. SPY Return is what SPY did over those same windows — reference only, not a comparison. The headline alpha number is Mean Excess = Insider − SPY; green means the filer beat SPY, red means they trailed it. Win rate is the share of individual trades where the filer beat SPY. T-statvalues above 2 mean the alpha is unlikely to be chance given the sample size. "Pending" counts trades where the horizon hasn't elapsed yet; their stats are not included in the row average.
Holdings over time
WTM · 1,703 shares · as of May 21, 2026
04338671,3001,733202120222023202420252026SHARES HELD
Trading cadence · quarterly flow
BUY SELL
2020
2020
2020
2021
2021
2021
2021
2022
2022
2022
2022
2023
2023
2023
2023
2024
2024
2024
2024
2025
2025
2025
2025
2026
2026
FLOW · 7 buys / 1 sellsCOVERAGE · 25 quarters
Form 4 filings · all activity
COMPANYTYPESHARESPRICEVALUEHELD AFTERTRADE DATEFILEDDETAILS
WTM
WHITE MOUNTAINS INSURANCE GROUP LTD
PURCHASEGRANT
Stock grant
1351,703May 21, 2026May 21, 2026View →
WTM
WHITE MOUNTAINS INSURANCE GROUP LTD
SALE
165$2,048.51$338.0K1,568Dec 16, 2025Dec 16, 2025View →
WTM
WHITE MOUNTAINS INSURANCE GROUP LTD
PURCHASEGRANT
Stock grant
1501,733May 22, 2025May 22, 2025View →
WTM
WHITE MOUNTAINS INSURANCE GROUP LTD
PURCHASEGRANT
Stock grant
1651,583May 23, 2024May 24, 2024View →
WTM
WHITE MOUNTAINS INSURANCE GROUP LTD
PURCHASEGRANT
Stock grant
1801,418May 25, 2023May 26, 2023View →
WTM
WHITE MOUNTAINS INSURANCE GROUP LTD
PURCHASEGRANT
Stock grant
2251,238May 26, 2022May 27, 2022View →
WTM
WHITE MOUNTAINS INSURANCE GROUP LTD
PURCHASEGRANT
Stock grant
2251,013May 27, 2021May 28, 2021View →
WTM
WHITE MOUNTAINS INSURANCE GROUP LTD
PURCHASEGRANT
Stock grant
225788May 21, 2020May 22, 2020View →
Other insiders · WTM
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About this filer
CIK 0001733327
ROLE
Director
PRIMARY
WTM
COMPANIES
1
ACTIVE SINCE
May 2020
MARKETPEEL · /INSIDER/0001733327DATA · SEC EDGAR · FORM 4 · CONSOLIDATED TAPE
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