undamentalytics Newsletter

Guerrero Ramiro: insider trades

Director at Maia Biotechnology, Inc. 10 open-market purchases and no sales not made under a pre-set plan, reported from September 13, 2022 to September 14, 2026.

Would copying Guerrero Ramiro’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. None of their purchases could be priced, so there is no copy portfolio. None of these trades can be measured yet: either the window after the report has not finished or the share price was under $5 when it was reported.

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

Guerrero Ramiro: 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 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
Maia Biotechnology, Inc. MAIA —100September 13, 2022September 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 10, 2026 MAIA Purchase $49,625 not yetnot yetnot yet
September 1, 2026August 26, 2026 MAIA Purchase $184,103 not yetnot yetnot yet
August 24, 2026August 20, 2026 MAIA Purchase $16,302 not yetnot yetnot yet
May 12, 2025May 8, 2025 MAIA Purchase $30,000 not yetnot yetnot yet
March 5, 2025March 3, 2025 MAIA Purchase $50,000 not yetnot yetnot yet
February 25, 2025February 24, 2025 MAIA Purchase $110,000 not yetnot yetnot yet
December 13, 2024December 13, 2024 MAIA Purchase $99,892 not yetnot yetnot yet
November 4, 2024November 1, 2024 MAIA Purchase $222,220 not yetnot yetnot yet
April 28, 2023April 27, 2023 MAIA Purchase $19,125 not yetnot yetnot yet
September 13, 2022September 13, 2022 MAIA Purchase $33,875 not yetnot yetnot yet

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