undamentalytics Newsletter

Corasanti Joseph J: insider trades

Chief executive, Director at 2 companies we cover. 4 open-market purchases and 23 sales not made under a pre-set plan, reported from May 13, 2010 to December 12, 2025.

Would copying Corasanti Joseph J’s purchases have beaten the S&P 500?

Too few purchases to judge. Only 4 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 August 12, 2011 into $16,781 by November 2, 2026, +3.5% a year. The copy held shares only 24% of the time, so the fair comparison is the S&P 500 on those same days with Treasury bills otherwise: $20,775, +4.9% a year (the S&P 500 held throughout made $83,592, +15.0% a year). Beta against the index was 0.60. Twelve months after each report, the average purchase was −6.0% against the S&P 500 (median −9.0%), and 50% beat it. Measured from the trade date, the insider’s own timing, the average was −2.9%. After their sales, the shares moved +13.6% against the index over 12 months on average (a negative figure means selling was the right call); 38% 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 $83.6k$20.8k$16.8k
Copying Corasanti Joseph JS&P 500, same days investedS&P 500, held throughout $10,000 copying Corasanti Joseph J’s open-market purchases from August 12, 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
+3.5%
S&P 500, same days invested
+4.9% (held throughout +15.0%)
Time in shares
24%
Sharpe ratio (S&P 500)
0.19 (0.81)
Biggest drop (S&P 500)
−49% (−34%)
Market sensitivity (beta)
0.60
Purchases copied
4

Trade by trade

Corasanti Joseph J: trades against the S&P 500 afterwards
MeasuredTrades countedAverage vs S&P 500MedianWent the right wayYearst-statisticp-valueEvidence
Purchases, 3 months after the report 4 −6.3% −9.8% 25% 4 −0.98 0.40 No reliable evidence
Purchases, 6 months after the report 4 −8.4% −8.5% 50% 4 −1.19 0.32 No reliable evidence
Purchases, 12 months after the report 4 −6.0% −9.0% 50% 4 −0.32 0.77 No reliable evidence
Purchases, 12 months after the trade 4 −2.9% −4.3% 50% 4 −0.16 0.88 No reliable evidence
Sales, 3 months after the report 23 +5.9% −1.1% 52% 13 1.13 0.28 No reliable evidence
Sales, 12 months after the report 21 +13.6% +10.0% 38% 12 2.20 0.050 No reliable evidence
Sales, 12 months after the trade 21 +12.3% +3.0% 38% 12 1.94 0.078 No reliable evidence

“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
Coherent Corp. COHR —412May 13, 2010December 12, 2025
Conmed Corp CNMD Former President & CEO011November 5, 2010July 31, 2014

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 12, 2025December 10, 2025 COHR Sale $2,951,100 +46.7%not yetnot yet
November 12, 2025November 7, 2025 COHR Sale $1,470,150 +55.2%not yetnot yet
November 27, 2024November 26, 2024 COHR Sale $935,920 −25.4%+55.8%+47.2%
September 16, 2024September 13, 2024 COHR Sale $694,188 +30.3%+20.4%+13.9%
June 5, 2024June 4, 2024 COHR Sale $752,752 +2.4%+10.0%+6.2%
June 2, 2023June 2, 2023 COHR Sale $317,403 −11.3%+49.4%+43.8%
September 15, 2022September 13, 2022 COHR Purchase $438,400 −17.8%−43.0%−39.0%
November 15, 2021November 12, 2021 COHR Sale $558,231 +17.6%−27.7%−27.7%
May 14, 2020May 13, 2020 COHR Sale $770,216 −1.8%+11.4%−10.7%
May 30, 2019May 30, 2019 COHR Purchase $103,488 +12.2%+37.2%+36.2%
August 13, 2018August 9, 2018 COHR Sale $1,800,618 −23.6%−21.2%−18.2%
March 20, 2017March 15, 2017 COHR Purchase $334,900 −9.9%+12.0%+17.3%
June 9, 2016June 7, 2016 COHR Sale $689,240 +6.4%+46.7%+40.8%
November 12, 2015November 11, 2015 COHR Sale $91,462 +15.3%+47.7%+47.0%
July 31, 2014July 30, 2014 CNMD Sale $4,279,624 +5.8%+39.3%+37.7%
October 30, 2013October 28, 2013 CNMD Sale $2,923,292 +15.6%+1.1%+3.1%
September 16, 2013September 12, 2013 CNMD Sale $1,481,858 +18.1%−2.1%+2.9%
March 6, 2013March 4, 2013 CNMD Sale $3,834,733 −1.2%+29.1%+31.3%
March 19, 2012March 15, 2012 CNMD Sale $751,750 −2.0%+0.2%+2.0%
August 11, 2011August 9, 2011 COHR Purchase $35,880 −9.7%−30.0%−26.0%
May 10, 2011May 9, 2011 CNMD Sale $90,079 −8.1%−5.4%−4.4%
May 9, 2011May 6, 2011 CNMD Sale $342,914 −6.8%−6.6%−4.5%
May 5, 2011May 4, 2011 CNMD Sale $41,464 −4.5%−4.5%−3.9%
May 4, 2011May 3, 2011 CNMD Sale $1,050,688 −2.3%−4.3%−3.6%
May 3, 2011April 29, 2011 CNMD Sale $2,823,218 −1.5%−3.9%−2.3%
November 5, 2010November 4, 2010 CNMD Sale $1,510,020 +12.1%+17.0%+13.8%
May 13, 2010May 11, 2010 COHR Sale $668,906 −1.8%+32.9%+43.6%

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