undamentalytics Newsletter

Rosati Mario M: insider trades

Director at 2 companies we cover. No open-market purchases and 18 sales not made under a pre-set plan, reported from February 16, 2017 to February 24, 2025.

What happened after Rosati Mario M’s sales?

After their sales, the shares moved −10.8% against the index over 12 months on average (a negative figure means selling was the right call); 60% 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

Rosati Mario M: 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 15 +3.6% +2.4% 47% 6 0.93 0.40 No reliable evidence
Sales, 12 months after the report 15 −10.8% −51.9% 60% 6 0.62 0.56 No reliable evidence
Sales, 12 months after the trade 15 −8.3% −52.5% 53% 6 0.66 0.54 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
Aehr Test Systems AEHR —013October 3, 2018June 12, 2023
Sanmina Corp SANM —05February 16, 2017February 24, 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
February 24, 2025February 21, 2025 SANM Sale $979,854 +3.6%+75.3%+68.6%
August 16, 2024August 14, 2024 SANM Sale $493,191 +2.4%+39.9%+51.9%
February 26, 2024February 23, 2024 SANM Sale $522,414 +4.2%+13.4%+19.1%
June 12, 2023June 6, 2023 AEHR Sale $71,336 +7.1%−93.9%−95.2%
February 9, 2023February 7, 2023 AEHR Sale $3,572,183 −10.7%−67.2%−75.7%
February 7, 2023February 3, 2023 AEHR Sale $1,915,750 −18.9%−73.8%−79.6%
February 6, 2023February 2, 2023 AEHR Sale $1,827,231 −22.6%−75.7%−79.9%
February 2, 2023January 31, 2023 AEHR Sale $3,131,857 −24.7%−79.6%−79.0%
January 18, 2023January 13, 2023 AEHR Sale $495,214 −8.3%−67.3%−61.7%
January 13, 2023January 11, 2023 AEHR Sale $1,200,410 +2.5%−61.4%−60.6%
October 11, 2022October 10, 2022 AEHR Sale $20,969 +76.0%+140.1%+119.0%
February 8, 2022February 7, 2022 AEHR Sale $30,700 −38.0%+117.1%+188.4%
September 30, 2021September 28, 2021 AEHR Sale $53,542 +82.1%+31.0%+11.4%
February 8, 2021February 4, 2021 SANM Sale $161,566 +10.7%−8.0%+1.2%
October 8, 2019October 8, 2019 AEHR Sale $70,003 not yetnot yetnot yet
January 22, 2019January 18, 2019 AEHR Sale $34,102 not yetnot yetnot yet
October 3, 2018October 2, 2018 AEHR Sale $21,800 not yetnot yetnot yet
February 16, 2017February 14, 2017 SANM Sale $67,380 −11.9%−51.9%−52.5%

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