ABOUT CONGRESSIONAL TRADING IN COST
As of May 2026, 22 members of Congress have collectively executed 44 disclosed trades on COST (Costco Wholesale Corporation -
Common Stock). This includes 23 purchases and 21 sales, with bipartisan cluster activity detected 1 time — instances where members of both parties traded COST within overlapping time windows, often a signal of coordinated information or policy-related activity.
MOST-ACTIVE TRADERS
The most active trader of COST on Signal Congress is Markwayne Mullin with 3 trades, followed by Kathy Manning (3 trades) and Gilbert Cisneros (3 trades).
Signal Congress tracks COST congressional trades through STOCK Act PTR filings from the House Clerk XML feed and Senate eFD system. Each trade is scored for conviction (0–100 scale) based on filing speed, amount, and corroboration signals, and analyzed for alpha generation against the SPY benchmark over 60-day and 180-day windows.