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Wahlstrom Mats: insider trades

Director at 2 companies we cover. 3 open-market purchases and 7 sales not made under a pre-set plan, reported from August 18, 2015 to May 18, 2026.

Would copying Wahlstrom Mats’s purchases have beaten the S&P 500?

Too few purchases to judge. None of their purchases has 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. After their sales, the shares moved −36.1% against the index over 12 months on average (a negative figure means selling was the right call); 100% trailed it. None of their purchases could be priced, so there is no copy portfolio.

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

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 6 −11.4% −10.8% 83% 3 — — Not enough years
Sales, 12 months after the report 6 −36.1% −30.1% 100% 3 — — Not enough years
Sales, 12 months after the trade 6 −40.6% −34.6% 100% 3 — — 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
Coherus Oncology, Inc. CHRS —07August 18, 2015May 28, 2025
Trisalus Life Sciences, Inc. TLSI —30November 22, 2024May 18, 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
May 18, 2026May 15, 2026 TLSI Purchase $151,800 not yetnot yetnot yet
May 28, 2025May 23, 2025 CHRS Sale $73,991 not yetnot yetnot yet
November 25, 2024November 22, 2024 TLSI Purchase $22,750 not yetnot yetnot yet
November 22, 2024November 20, 2024 TLSI Purchase $47,057 not yetnot yetnot yet
June 19, 2020June 17, 2020 CHRS Sale $3,430,000 +3.3%−52.7%−53.6%
March 5, 2020March 3, 2020 CHRS Sale $2,375,324 −11.1%−48.4%−50.6%
December 9, 2016December 7, 2016 CHRS Sale $1,474,456 −25.3%−89.4%−89.2%
August 20, 2015August 18, 2015 CHRS Sale $213,496 −15.2%−11.7%−13.4%
August 19, 2015August 17, 2015 CHRS Sale $272,229 −10.6%−6.1%−17.9%
August 18, 2015August 14, 2015 CHRS Sale $3,990,809 −9.5%−8.3%−18.7%

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