MarketPeel
Insider Trading Intelligence
WB

William George Brumder

GPRO
10% OWNER · GOPRO, INC. · CIK 0002075341
FILING MIX · LIFETIME0%/100%
BUYS
0
SELLS
1
TOTAL VALUE
$29.9K
COMPANIES
1
ACTIVE SINCE
Sep 2025
HOLDINGS NOW
10,838,000
AVG SELL PX
$2.49
TRADE KIND
SHOWING 1 / 1
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 William George Brumder, 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+100.00%-5.76%-0.28%-5.48%-5.48%
14d1+100.00%-7.00%+0.83%-7.83%-7.83%
30d1+100.00%-11.93%+1.15%-13.08%-13.08%
60d1+100.00%-35.39%-0.55%-34.85%-34.85%
90d1+100.00%-34.57%+1.92%-36.49%-36.49%
180d1+100.00%-71.11%-0.34%-70.77%-70.77%
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
Not enough transaction history to chart holdings.
Trading cadence · quarterly flow
BUY SELL
2025
FLOW · 0 buys / 1 sellsCOVERAGE · 1 quarters
Form 4 filings · all activity
COMPANYTYPESHARESPRICEVALUEHELD AFTERTRADE DATEFILEDDETAILS
GPRO
GOPRO, INC.
SALE
12,000$2.49$29.9K10,838,000Sep 19, 2025Sep 26, 2025View →
Other insiders · GPRO
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About this filer
CIK 0002075341
ROLE
10% Owner
PRIMARY
GPRO
COMPANIES
1
ACTIVE SINCE
Sep 2025
MARKETPEEL · /INSIDER/0002075341DATA · SEC EDGAR · FORM 4 · CONSOLIDATED TAPE
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