undamentalytics Newsletter

Baker Felix: insider trades

Director, 10% owner at 10 companies we cover. 22 open-market purchases and 6 sales not made under a pre-set plan, reported from September 23, 2010 to December 11, 2025.

Would copying Baker Felix’s purchases have beaten the S&P 500?

Too few purchases to judge. Only 18 purchases have 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 December 13, 2011 into $2,452 by November 2, 2026, −9.0% a year. The copy held shares only 61% of the time, so the fair comparison is the S&P 500 on those same days with Treasury bills otherwise: $43,750, +10.4% a year (the S&P 500 held throughout made $79,830, +15.0% a year). Beta against the index was 0.89. Twelve months after each report, the average purchase was +3.6% against the S&P 500 (median −0.2%), and 44% beat it. Measured from the trade date, the insider’s own timing, the average was +14.5%. After their sales, the shares moved −10.5% against the index over 12 months on average (a negative figure means selling was the right call); 83% 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$25.0k$50.0k$75.0k 20112013201520172019202120232025 $79.8k$43.8k$2.5k
Copying Baker FelixS&P 500, same days investedS&P 500, held throughout $10,000 copying Baker Felix’s open-market purchases from December 13, 2011, 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
−9.0%
S&P 500, same days invested
+10.4% (held throughout +15.0%)
Time in shares
61%
Sharpe ratio (S&P 500)
0.16 (0.83)
Biggest drop (S&P 500)
−94% (−34%)
Market sensitivity (beta)
0.89
Purchases copied
20

Trade by trade

Baker Felix: trades against the S&P 500 afterwards
MeasuredTrades countedAverage vs S&P 500MedianWent the right wayYearst-statisticp-valueEvidence
Purchases, 3 months after the report 20 +7.8% +11.6% 55% 9 0.49 0.64 No reliable evidence
Purchases, 6 months after the report 20 −4.1% −6.9% 35% 9 −0.02 0.98 No reliable evidence
Purchases, 12 months after the report 18 +3.6% −0.2% 44% 9 0.37 0.72 No reliable evidence
Purchases, 12 months after the trade 18 +14.5% +16.0% 67% 10 0.54 0.60 No reliable evidence
Sales, 3 months after the report 6 +8.4% +2.6% 0% 3 — — Not enough years
Sales, 12 months after the report 6 −10.5% −9.4% 83% 3 — — Not enough years
Sales, 12 months after the trade 6 −11.2% −11.9% 83% 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
Incyte INCY —54September 23, 2010February 22, 2022
Kodiak Sciences Inc. KOD —50December 6, 2019May 27, 2022
Neurogene Inc. NGNE —40September 11, 2015August 8, 2019
Acadia Pharmaceuticals Inc ACAD —20April 1, 2016March 18, 2020
Beone Medicines Ltd. ONC —02December 4, 2020January 6, 2021
Madrigal Pharmaceuticals, Inc. MDGL —20November 15, 2023August 20, 2025
Biocryst Pharmaceuticals Inc BCRX —10February 9, 2016February 9, 2016
Kala BIO, Inc. KALA —10December 31, 2024December 31, 2024
Entrada Therapeutics, Inc. TRDA —10November 24, 2025November 24, 2025
Kymera Therapeutics, Inc. KYMR —10December 11, 2025December 11, 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
December 11, 2025December 11, 2025 KYMR Purchase $172,499,918 −8.1%not yetnot yet
November 24, 2025November 20, 2025 TRDA Purchase $261,824 +16.0%not yetnot yet
August 20, 2025August 18, 2025 MDGL Purchase $24,979,848 +31.9%+4.3%+17.1%
December 31, 2024December 30, 2024 KALA Purchase $2,000,000 −31.7%−111.2%−108.5%
November 15, 2023November 13, 2023 MDGL Purchase $15,801,067 +25.4%+47.5%+78.4%
May 27, 2022May 25, 2022 KOD Purchase $2,363,408 +48.2%−16.2%−17.5%
February 22, 2022February 17, 2022 INCY Purchase $35,733,665 +16.8%+17.8%+22.9%
January 25, 2022January 21, 2022 KOD Purchase $28,807,674 −86.0%−80.8%−78.9%
January 6, 2021January 4, 2021 ONC Sale $26,714,457 +9.4%−38.6%−28.0%
December 4, 2020December 4, 2020 ONC Sale $333,295,893 +30.4%+13.2%+8.5%
September 25, 2020September 25, 2020 KOD Purchase $2,726,182 +150.5%+42.9%+46.8%
March 18, 2020March 16, 2020 KOD Purchase $5,893,696 +19.2%+136.9%+151.9%
March 18, 2020March 16, 2020 ACAD Purchase $33,649,778 +11.5%−85.7%−81.8%
December 6, 2019December 6, 2019 KOD Purchase $87,499,958 −8.5%+72.1%+73.9%
August 8, 2019August 6, 2019 NGNE Purchase $1,114,660 not yetnot yetnot yet
September 21, 2016September 20, 2016 NGNE Purchase $34,110,456 −3.2%−25.5%−15.0%
April 1, 2016March 30, 2016 ACAD Purchase $39,238,724 +11.6%−3.2%+21.2%
February 16, 2016February 11, 2016 INCY Purchase $143,026,261 −5.3%+38.0%+56.4%
February 9, 2016February 5, 2016 BCRX Purchase $284,850 not yetnot yetnot yet
January 15, 2016January 14, 2016 NGNE Purchase $1,676,926 −14.9%+74.8%+97.7%
September 11, 2015September 10, 2015 NGNE Purchase $38,440,496 −37.9%−39.5%−37.1%
January 17, 2012January 12, 2012 INCY Purchase $8,893,702 −5.0%−6.8%+2.9%
December 12, 2011December 8, 2011 INCY Purchase $5,395,313 +13.1%−0.2%+14.9%
December 12, 2011December 8, 2011 INCY Purchase $144,763 +13.1%−0.2%+14.9%
September 23, 2010September 21, 2010 INCY Sale $15,124,200 +2.6%−9.4%−11.9%
September 23, 2010September 21, 2010 INCY Sale $5,905,921 +2.6%−9.4%−11.9%
September 23, 2010September 21, 2010 INCY Sale $481,755 +2.6%−9.4%−11.9%
September 23, 2010September 21, 2010 INCY Sale $478,245 +2.6%−9.4%−11.9%

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 Baker Felix traded and do not suggest the use of non-public information. How every insider compares · the insider trading backtest.