Stanford and SMU researchers document settlement manipulation in Polymarket Bitcoin prediction markets, with 821 identified manipulators extracting $8.2M from retail traders via coordinated spot orders on Binance.
DeFi & Yields ·
Researchers from Stanford University and Singapore Management University documented signs of settlement manipulation in Polymarket's Bitcoin prediction markets, finding that traders were placing large one-sided spot orders on Binance seconds before market settlement to shift the reference price. Analysis of roughly two months of trading data revealed a pattern in which prices would move sharply toward a given outcome in the final moments before settlement, then reverse just as quickly.
The study identified 821 likely manipulators who extracted approximately $8.2 million from the affected markets. Retail traders bore the majority of losses from these activities. The research focused on Polymarket's five-minute Bitcoin prediction markets, which appear to be particularly susceptible to this settlement-timing strategy given their short duration and reliance on external price feeds.
The analysis documents the mechanics of the manipulation but leaves unresolved the question of how widespread or systematic this behavior is across other prediction markets and asset pairs, as well as what structural changes to settlement mechanisms or market design might effectively prevent such tactics.