undamentalytics Newsletter

Read Brian: insider trades

Chief financial officer at Serve Robotics Inc. No open-market purchases and 25 sales not made under a pre-set plan, reported from May 13, 2025 to August 19, 2026.

What happened after Read Brian’s sales?

After their sales, the shares moved −69.0% against the index over 12 months on average (a negative figure means selling was the right call); 100% 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

Read Brian: 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 24 −16.1% −19.9% 79% 2 — — Not enough years
Sales, 12 months after the report 13 −69.0% −71.8% 100% 1 — — Not enough years
Sales, 12 months after the trade 14 −70.1% −72.7% 100% 1 — — 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
Serve Robotics Inc. SERV Chief Financial Officer025May 13, 2025August 19, 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
August 19, 2026August 17, 2026 SERV Sale $206,766 not yetnot yetnot yet
June 11, 2026June 10, 2026 SERV Sale $10,831 −39.3%not yetnot yet
May 8, 2026May 6, 2026 SERV Sale $27,780 −49.1%not yetnot yet
May 4, 2026May 1, 2026 SERV Sale $10,953 −44.7%not yetnot yet
April 1, 2026March 31, 2026 SERV Sale $10,142 −38.5%not yetnot yet
March 4, 2026March 3, 2026 SERV Sale $12,185 −24.5%not yetnot yet
February 5, 2026February 3, 2026 SERV Sale $49,655 −24.9%not yetnot yet
December 31, 2025December 31, 2025 SERV Sale $19,319 −26.1%not yetnot yet
December 15, 2025December 11, 2025 SERV Sale $92,509 −11.1%not yetnot yet
December 5, 2025December 4, 2025 SERV Sale $97,875 −19.9%not yetnot yet
December 3, 2025December 2, 2025 SERV Sale $20,200 −26.4%not yetnot yet
October 30, 2025October 30, 2025 SERV Sale $16,916 −19.8%not yet−93.2%
September 30, 2025September 30, 2025 SERV Sale $14,332 −14.1%−77.2%−75.1%
September 18, 2025September 18, 2025 SERV Sale $50,051 −29.5%−85.2%−83.8%
September 11, 2025September 11, 2025 SERV Sale $49,841 +0.8%−80.8%−78.1%
September 8, 2025September 8, 2025 SERV Sale $74,932 +18.8%−76.9%−74.5%
September 2, 2025September 2, 2025 SERV Sale $13,539 −3.6%−71.8%−73.5%
August 25, 2025August 25, 2025 SERV Sale $100,321 −10.7%−73.3%−72.0%
August 18, 2025August 18, 2025 SERV Sale $100,115 −11.5%−71.2%−74.3%
August 6, 2025August 5, 2025 SERV Sale $27,579 +2.8%−77.2%−70.9%
July 30, 2025July 30, 2025 SERV Sale $12,678 +26.9%−65.8%−71.8%
July 1, 2025July 1, 2025 SERV Sale $13,982 −0.5%−63.5%−64.0%
June 9, 2025June 9, 2025 SERV Sale $25,180 −20.3%−62.2%−66.8%
June 2, 2025May 30, 2025 SERV Sale $14,983 −24.1%−55.6%−52.8%
May 13, 2025May 13, 2025 SERV Sale $79,655 +2.6%−36.0%−30.8%

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