undamentalytics Newsletter

Miller Matthew Reade: insider trades

Director at Granite Ridge Resources, Inc. 20 open-market purchases and no sales not made under a pre-set plan, reported from May 30, 2023 to September 14, 2026.

Would copying Miller Matthew Reade’s purchases have beaten the S&P 500?

Too few purchases to judge. Only 15 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 May 31, 2023 into $11,755 by November 2, 2026, +4.9% a year. The copy held shares only 100% of the time, so the fair comparison is the S&P 500 on those same days with Treasury bills otherwise: $18,909, +20.6% a year (the S&P 500 held throughout made $18,909, +20.6% a year). Beta against the index was 0.69. Twelve months after each report, the average purchase was −20.1% against the S&P 500 (median −21.8%), and 7% beat it. Measured from the trade date, the insider’s own timing, the average was −19.6%.

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 2023202420252026 $18.9k$18.9k$11.8k
Copying Miller Matthew ReadeS&P 500, same days investedS&P 500, held throughout $10,000 copying Miller Matthew Reade’s open-market purchases from May 31, 2023, 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
+4.9%
S&P 500, same days invested
+20.6% (held throughout +20.6%)
Time in shares
100%
Sharpe ratio (S&P 500)
0.21 (1.02)
Biggest drop (S&P 500)
−37% (−19%)
Market sensitivity (beta)
0.69
Purchases copied
20

Trade by trade

Miller Matthew Reade: trades against the S&P 500 afterwards
MeasuredTrades countedAverage vs S&P 500MedianWent the right wayYearst-statisticp-valueEvidence
Purchases, 3 months after the report 19 −2.6% −5.8% 26% 4 −0.60 0.59 No reliable evidence
Purchases, 6 months after the report 17 −9.3% −8.5% 6% 4 −5.21 0.014 Some evidence: behind
Purchases, 12 months after the report 15 −20.1% −21.8% 7% 3 — — Not enough years
Purchases, 12 months after the trade 15 −19.6% −20.3% 0% 3 — — Not enough years
Sales, 3 months after the report 0 — — — — — — Not enough years
Sales, 12 months after the report 0 — — — — — — Not enough years
Sales, 12 months after the trade 0 — — — — — — 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
Granite Ridge Resources, Inc. GRNT —200May 30, 2023September 14, 2026

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
September 14, 2026September 11, 2026 GRNT Purchase $50,300 not yetnot yetnot yet
June 9, 2026June 9, 2026 GRNT Purchase $50,350 −0.7%not yetnot yet
May 13, 2026May 13, 2026 GRNT Purchase $94,718 −5.8%not yetnot yet
March 11, 2026March 10, 2026 GRNT Purchase $51,000 −14.2%not yetnot yet
December 5, 2025December 4, 2025 GRNT Purchase $50,038 +1.4%not yetnot yet
August 12, 2025August 12, 2025 GRNT Purchase $100,232 −7.8%−19.2%−20.4%
June 16, 2025June 16, 2025 GRNT Purchase $101,660 −17.4%−42.2%−38.5%
December 6, 2024December 6, 2024 GRNT Purchase $250,100 +0.6%−24.6%−20.3%
November 21, 2024November 21, 2024 GRNT Purchase $134,158 −9.3%−32.8%−32.0%
November 21, 2024November 20, 2024 GRNT Purchase $117,943 −9.3%−32.8%−31.4%
September 11, 2024September 11, 2024 GRNT Purchase $50,745 −7.3%−21.8%−24.2%
August 22, 2024August 22, 2024 GRNT Purchase $25,320 −2.5%−25.4%−20.3%
August 16, 2024August 16, 2024 GRNT Purchase $32,097 −5.6%−25.6%−29.8%
June 17, 2024June 14, 2024 GRNT Purchase $50,150 +5.9%+5.0%−1.1%
June 4, 2024June 3, 2024 GRNT Purchase $50,050 −6.2%−15.3%−18.5%
March 18, 2024March 14, 2024 GRNT Purchase $30,413 −10.8%−8.9%−7.5%
December 13, 2023December 12, 2023 GRNT Purchase $15,418 −7.0%−25.6%−19.8%
September 19, 2023September 18, 2023 GRNT Purchase $99,729 −2.2%−18.8%−11.0%
May 31, 2023May 30, 2023 GRNT Purchase $23,400 +19.0%−9.1%−6.7%
May 30, 2023May 25, 2023 GRNT Purchase $23,660 +29.4%−5.2%−13.4%

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