undamentalytics Newsletter

Sayiner Necip: insider trades

Director at 4 companies we cover. No open-market purchases and 15 sales not made under a pre-set plan, reported from August 6, 2020 to June 4, 2026.

What happened after Sayiner Necip’s sales?

After their sales, the shares moved −2.9% against the index over 12 months on average (a negative figure means selling was the right call); 50% 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

Sayiner Necip: 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 +4.9% −8.4% 60% 6 0.40 0.70 No reliable evidence
Sales, 12 months after the report 10 −2.9% −10.9% 50% 5 0.59 0.59 No reliable evidence
Sales, 12 months after the trade 10 −2.2% −9.3% 60% 5 0.61 0.57 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
Rambus Inc RMBS —08November 16, 2022June 3, 2026
Power Integrations Inc POWI —04August 6, 2020May 30, 2023
Sandisk SNDK —02December 4, 2025May 11, 2026
Axcelis Technologies Inc ACLS —01June 4, 2026June 4, 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
June 4, 2026June 3, 2026 ACLS Sale $249,700 −26.5%not yetnot yet
June 3, 2026June 3, 2026 RMBS Sale $850,750 −52.6%not yetnot yet
May 11, 2026May 8, 2026 SNDK Sale $870,301 −12.3%not yetnot yet
May 11, 2026May 8, 2026 RMBS Sale $1,278,888 −27.4%not yetnot yet
December 4, 2025December 3, 2025 SNDK Sale $248,023 +171.8%not yetnot yet
September 12, 2025September 11, 2025 RMBS Sale $642,225 −4.1%−29.6%−26.2%
August 11, 2025August 8, 2025 RMBS Sale $551,475 +38.4%+7.6%+10.1%
February 19, 2025February 19, 2025 RMBS Sale $308,672 −11.7%+33.6%+40.9%
November 7, 2023November 6, 2023 RMBS Sale $574,300 −18.2%−46.6%−37.8%
May 30, 2023May 26, 2023 POWI Sale $404,775 −11.2%−39.1%−42.5%
February 16, 2023February 14, 2023 POWI Sale $104,298 +1.0%−35.3%−32.8%
February 13, 2023February 10, 2023 RMBS Sale $130,808 +15.8%+0.3%−1.0%
November 16, 2022November 15, 2022 RMBS Sale $572,400 +14.1%+69.6%+55.4%
August 27, 2021August 25, 2021 POWI Sale $261,325 −8.4%−22.1%−17.5%
August 6, 2020August 4, 2020 POWI Sale $207,293 +4.5%+33.0%+29.1%

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