undamentalytics Newsletter

Gordon Carl L: insider trades

Director at 5 companies we cover. 8 open-market purchases and 10 sales not made under a pre-set plan, reported from March 2, 2011 to April 11, 2025.

Would copying Gordon Carl L’s purchases have beaten the S&P 500?

Too few purchases to judge. Only 1 purchase has 12 months of prices after the report; we judge insiders once they have 20. The figures below can swing a long way on a handful of trades. Buying each purchase the day after it was reported, an equal amount each, and holding it 12 months or until they reported a sale would have turned $10,000 on February 20, 2025 into $30,214 by November 2, 2026, +92.0% a year. The copy held shares only 59% of the time, so the fair comparison is the S&P 500 on those same days with Treasury bills otherwise: $11,741, +9.9% a year (the S&P 500 held throughout made $12,637, +14.8% a year). Beta against the index was 0.99. Twelve months after each report, the average purchase was +197.5% against the S&P 500 (median +197.5%), and 100% beat it. Measured from the trade date, the insider’s own timing, the average was +273.3%. After their sales, the shares moved −14.0% against the index over 12 months on average (a negative figure means selling was the right call); 56% trailed it.

With 296 insiders tested, some will look skilled or unskilled by chance alone: when we replaced each insider’s stocks with random companies bought on the same days, about 5.7 cleared the bar ahead and 23.3 behind. One record on its own proves little.

$0$10.0k$20.0k$30.0k 20252026 $30.2k$12.6k$11.7k
Copying Gordon Carl LS&P 500, same days investedS&P 500, held throughout $10,000 copying Gordon Carl L’s open-market purchases from February 20, 2025, before costs and taxes, marked weekly. Each purchase gets the same starting stake, bought at the close of the first trading day after the report and sold 12 months later or the day after a reported sale of that stock; uninvested money earns the Treasury bill rate. “Same days invested” holds the S&P 500 only on the days the copy held shares, Treasury bills otherwise.
Return a year, copying
+92.0%
S&P 500, same days invested
+9.9% (held throughout +14.8%)
Time in shares
59%
Sharpe ratio (S&P 500)
1.00 (0.66)
Biggest drop (S&P 500)
−51% (−18%)
Market sensitivity (beta)
0.99
Purchases copied
1

Trade by trade

Gordon Carl L: trades against the S&P 500 afterwards
MeasuredTrades countedAverage vs S&P 500MedianWent the right wayYearst-statisticp-valueEvidence
Purchases, 3 months after the report 1 +7.8% +7.8% 100% 1 — — Not enough years
Purchases, 6 months after the report 1 +14.9% +14.9% 100% 1 — — Not enough years
Purchases, 12 months after the report 1 +197.5% +197.5% 100% 1 — — Not enough years
Purchases, 12 months after the trade 1 +273.3% +273.3% 100% 1 — — Not enough years
Sales, 3 months after the report 9 +64.2% +96.7% 22% 3 — — Not enough years
Sales, 12 months after the report 9 −14.0% −2.3% 56% 3 — — Not enough years
Sales, 12 months after the trade 9 −13.8% −8.3% 56% 3 — — Not enough years

“Average vs S&P 500” is the stock’s return including dividends minus the index’s over the same dates, from the close on the first trading day after the report, or from the close on the trade date. Only windows that have finished are counted. For sales, a negative figure means the stock lagged after it was sold, so selling was the right call (green). “Went the right way” is the share of purchases that beat the index, or of sales that trailed it. The t-statistic uses one average per year of reports, because one person’s trades bunch into the same stock and weeks, and needs trades in at least four different years; the p-value comes from the t distribution with that number of years (with four years, a t of 2 has p = 0.14). “Some evidence” means p under 5%, “strong evidence” p under 1% over at least six years.

Companies traded

CompanyTitle on the latest filingPurchasesSalesFirst reportLatest report
Amarin Corp plc\uk AMRN —08March 2, 2011June 19, 2012
Compass Therapeutics, Inc. CMPX —51June 23, 2020April 11, 2025
Adicet Bio, Inc. ACET —20June 29, 2023January 26, 2024
Keros Therapeutics, Inc. KROS —01August 15, 2024August 15, 2024
MBX Biosciences, Inc. MBX —10February 19, 2025February 19, 2025

Trades and what followed

Moves are against the S&P 500; green means the trade went the insider’s way.

ReportedTradedCompanyTradeValue3 months after report12 months after report12 months after trade
April 11, 2025April 9, 2025 CMPX Sale $5,678,571 not yetnot yetnot yet
February 19, 2025February 14, 2025 MBX Purchase $2,020,756 +7.8%+197.5%+273.3%
August 15, 2024August 13, 2024 KROS Sale $11,002,500 +25.1%−85.3%−87.7%
January 26, 2024January 25, 2024 ACET Purchase $7,500,000 not yetnot yetnot yet
June 29, 2023June 27, 2023 ACET Purchase $1,828,750 not yetnot yetnot yet
November 10, 2022November 8, 2022 CMPX Purchase $1,290,420 not yetnot yetnot yet
May 13, 2022May 11, 2022 CMPX Purchase $420,482 not yetnot yetnot yet
May 10, 2022May 6, 2022 CMPX Purchase $197,252 not yetnot yetnot yet
November 8, 2021November 4, 2021 CMPX Purchase $18,750,000 not yetnot yetnot yet
June 23, 2020June 19, 2020 CMPX Purchase $7,275,660 not yetnot yetnot yet
June 19, 2012June 19, 2012 AMRN Sale $7,985,051 +2.2%−72.3%−70.4%
May 3, 2011April 29, 2011 AMRN Sale $2,137,270 −13.6%−26.9%−28.4%
April 25, 2011April 21, 2011 AMRN Sale $12,500,000 −10.6%−42.5%−44.8%
March 28, 2011March 24, 2011 AMRN Sale $1,281,828 +104.4%+44.4%+48.7%
March 23, 2011March 21, 2011 AMRN Sale $542,850 +96.7%+48.7%+58.4%
March 15, 2011March 11, 2011 AMRN Sale $1,654,750 +97.8%+10.1%−8.3%
March 7, 2011March 3, 2011 AMRN Sale $573,980 +128.0%−2.3%+0.4%
March 2, 2011February 28, 2011 AMRN Sale $1,884,400 +147.5%+0.4%+7.5%

Open-market purchases and sales of at least $10,000 in companies we cover, from SEC Form 4 filings; sales made under a pre-set Rule 10b5-1 plan are not shown. “Not yet” means the window has not finished or the share price was under $5 at entry. These are the shares’ moves after each trade: they say nothing about why Gordon Carl L traded and do not suggest the use of non-public information. How every insider compares · the insider trading backtest.