We tested four ways to trade news on Polymarket in 2026, on non-sports event markets: a 5-second bot, following a move a minute late, copying wallets that were early on past news, and copying fresh wallets that agree. None made money. The full results are on our blog , and every price shock and detector trigger is on GitHub with a standard-library script that recomputes the tables.

This post is about the one test that did look profitable, because the reason is a bug that is very easy to write into any event-driven backtest.

The bot that made +$2.63 per $10

The idea: Polymarket prices react to headlines, and a bot that sees the first trade of a move can buy within seconds. Our first backtest bought $10 in the direction of a news move 5 seconds after its first trade, paid the taker fee, and valued the position at the price 2 to 15 minutes later.

Result: +$2.63 per $10, t-statistic 10.1, on 510 events.…