undamentalytics Newsletter

Murphy Patrick Michael: insider trades

Officer at 2 companies we cover. No open-market purchases and 18 sales not made under a pre-set plan, reported from March 13, 2019 to August 11, 2026.

What happened after Murphy Patrick Michael’s sales?

After their sales, the shares moved +10.6% against the index over 12 months on average (a negative figure means selling was the right call); 57% 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.

Trade by trade

Murphy Patrick Michael: trades against the S&P 500 afterwards
MeasuredTrades countedAverage vs S&P 500MedianWent the right wayYearst-statisticp-valueEvidence
Purchases, 3 months after the report 0 — — — — — — Not enough years
Purchases, 6 months after the report 0 — — — — — — Not enough years
Purchases, 12 months after the report 0 — — — — — — Not enough years
Purchases, 12 months after the trade 0 — — — — — — Not enough years
Sales, 3 months after the report 17 +1.9% −3.8% 53% 8 0.45 0.66 No reliable evidence
Sales, 12 months after the report 14 +10.6% −1.8% 57% 7 0.42 0.69 No reliable evidence
Sales, 12 months after the trade 14 +10.7% −1.1% 57% 7 0.35 0.73 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
Irhythm Holdings, Inc. IRTC CBO and CLO012December 6, 2022August 11, 2026
Dexcom DXCM EVP, Chief Legal Officer06March 13, 2019September 13, 2021

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
August 11, 2026August 10, 2026 IRTC Sale $884,142 not yetnot yetnot yet
March 3, 2026March 2, 2026 IRTC Sale $559,624 −28.7%not yetnot yet
February 26, 2026February 25, 2026 IRTC Sale $1,056,953 −25.4%not yetnot yet
December 3, 2025December 2, 2025 IRTC Sale $458,009 −31.2%not yetnot yet
March 4, 2025March 3, 2025 IRTC Sale $334,468 +31.1%−1.9%−1.5%
February 27, 2025February 26, 2025 IRTC Sale $1,791,041 +28.0%−1.6%+5.5%
December 3, 2024December 2, 2024 IRTC Sale $214,038 +20.3%+85.8%+91.6%
March 5, 2024March 4, 2024 IRTC Sale $169,488 −21.5%−20.7%−20.3%
March 1, 2024February 29, 2024 IRTC Sale $928,725 −26.3%−20.3%−24.6%
December 6, 2023December 5, 2023 IRTC Sale $149,751 +11.5%−38.4%−39.6%
March 7, 2023March 3, 2023 IRTC Sale $66,938 −21.7%−36.4%−37.1%
December 6, 2022December 2, 2022 IRTC Sale $181,953 +10.4%−28.3%−36.8%
September 13, 2021September 9, 2021 DXCM Sale $534,327 −4.0%−23.3%−24.6%
March 12, 2021March 10, 2021 DXCM Sale $1,259,695 +5.4%+5.9%+4.5%
September 11, 2020September 9, 2020 DXCM Sale $973,445 −20.3%+4.6%+3.5%
March 13, 2020March 11, 2020 DXCM Sale $1,080,810 +68.3%+7.2%−0.8%
September 11, 2019September 9, 2019 DXCM Sale $373,895 +39.5%+147.5%+153.8%
March 13, 2019March 12, 2019 DXCM Sale $565,734 −3.8%+68.6%+75.5%

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