MarketPeel
Insider Trading Intelligence
GR

George Manning Rountree

WTM
CHIEF EXECUTIVE OFFICER · WHITE MOUNTAINS INSURANCE GROUP LTD · CIK 0001457475
FILING MIX · LIFETIME46%/54%
BUYS
6
SELLS
7
TOTAL VALUE
$19.16M
COMPANIES
1
ACTIVE SINCE
Jan 2020
HOLDINGS NOW
13,809
AVG SELL PX
$1,628.62
TRADE KIND
SHOWING 13 / 13
Trades · vs SPY
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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 George Manning Rountree, 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%+0.99%+1.43%-0.43%-0.43%
14d1+100.00%-0.01%+0.38%-0.39%-0.39%
30d1+0.00%+0.70%+1.63%-0.92%-0.92%
60d1+0.00%+9.25%+0.33%+8.91%+8.91%
90d1+0.00%+6.81%-3.06%+9.87%+9.87%
180d1+100.00%-0.47%+10.25%-10.72%-10.72%
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 · 13,809 shares · as of Dec 19, 2025
04,7029,40514,10718,809202020212022202320242025SHARES HELD
Trading cadence · quarterly flow
BUY SELL
2020
2020
2020
2020
2021
2021
2021
2021
2022
2022
2022
2022
2023
2023
2023
2023
2024
2024
2024
2024
2025
2025
2025
2025
FLOW · 6 buys / 7 sellsCOVERAGE · 24 quarters
Form 4 filings · all activity
COMPANYTYPESHARESPRICEVALUEHELD AFTERTRADE DATEFILEDDETAILS
WTM
WHITE MOUNTAINS INSURANCE GROUP LTD
SALE
Chief Executive Officer
5,000$2,050.00$10.25M13,809Dec 19, 2025Dec 22, 2025View →
WTM
WHITE MOUNTAINS INSURANCE GROUP LTD
PURCHASEGRANT
Stock grant
1,6255,425Feb 26, 2025Feb 27, 2025View →
WTM
WHITE MOUNTAINS INSURANCE GROUP LTD
SALE
Chief Executive Officer
1,067$1,945.06$2.08M18,809Jan 1, 2025Jan 2, 2025View →
WTM
WHITE MOUNTAINS INSURANCE GROUP LTD
PURCHASEGRANT
Stock grant
1,8006,500Feb 22, 2024Feb 23, 2024View →
WTM
WHITE MOUNTAINS INSURANCE GROUP LTD
SALE
Chief Executive Officer
1,068$1,505.01$1.61M17,176Jan 1, 2024Jan 2, 2024View →
WTM
WHITE MOUNTAINS INSURANCE GROUP LTD
PURCHASEGRANT
Stock grant
2,0007,400Feb 22, 2023Feb 24, 2023View →
WTM
WHITE MOUNTAINS INSURANCE GROUP LTD
SALE
Chief Executive Officer
1,068$1,414.33$1.51M15,544Jan 1, 2023Jan 3, 2023View →
WTM
WHITE MOUNTAINS INSURANCE GROUP LTD
PURCHASEGRANT
Stock grant
2,7008,100Feb 25, 2022Feb 28, 2022View →
WTM
WHITE MOUNTAINS INSURANCE GROUP LTD
SALE
Chief Executive Officer
1,187$1,013.90$1.20M13,912Jan 1, 2022Jan 4, 2022View →
WTM
WHITE MOUNTAINS INSURANCE GROUP LTD
PURCHASEGRANT
Stock grant
2,7008,400Feb 25, 2021Feb 26, 2021View →
WTM
WHITE MOUNTAINS INSURANCE GROUP LTD
SALE
Chief Executive Officer
1,187$1,000.66$1.19M12,099Jan 1, 2021Jan 4, 2021View →
WTM
WHITE MOUNTAINS INSURANCE GROUP LTD
PURCHASEGRANT
Stock grant
2,7008,700Feb 27, 2020Mar 2, 2020View →
WTM
WHITE MOUNTAINS INSURANCE GROUP LTD
SALE
Chief Executive Officer
1,186$1,115.51$1.32M10,286Jan 1, 2020Jan 2, 2020View →
Other insiders · WTM
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About this filer
CIK 0001457475
ROLE
Chief Executive Officer
PRIMARY
WTM
COMPANIES
1
ACTIVE SINCE
Jan 2020
MARKETPEEL · /INSIDER/0001457475DATA · SEC EDGAR · FORM 4 · CONSOLIDATED TAPE
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