A new study from Stanford researchers has found that Polymarket’s five-minute Bitcoin price prediction contracts functioned as a wealth transfer mechanism, funneling approximately $8.2 million from retail traders to a small group of sophisticated participants who manipulated the market.
The study analyzed trading patterns on Polymarket’s ultra-short-term Bitcoin contracts, which settle every five minutes based on Bitcoin’s spot price. The researchers identified 821 traders who appeared to coordinate their activity to influence settlement prices in their favor. These traders placed orders on Binance, the largest spot exchange, in the final seconds before each contract settled.
By pushing Bitcoin’s price in a desired direction during the settlement window, these traders could determine which side of the Polymarket contract paid out. The study found that this manipulation distorted Bitcoin’s spot price during those brief windows, creating artificial price movements that did not reflect genuine supply and demand.
The research highlights a structural vulnerability in prediction markets that settle based on real-world asset prices. When a market’s payout depends on a price snapshot at a precise moment, traders with sufficient capital can influence that snapshot by trading on the underlying exchange. This is particularly feasible for short-duration contracts where a relatively small amount of capital can move the price temporarily.
Polymarket has faced growing regulatory scrutiny globally. Multiple US states have ordered the platform to halt certain prediction markets, and European regulators have warned that some of its offerings may violate binary options bans. The Stanford study adds to the body of evidence suggesting that prediction markets, particularly those with short settlement windows, can be vulnerable to manipulation.
The study’s authors recommend that prediction market platforms implement safeguards such as randomizing settlement times, using volume-weighted average prices rather than spot prices, and monitoring for coordinated trading activity across exchanges.
This article was adapted from Bitcoin Magazine. Read the original here.
