Uniswap founder interprets prediction market pricing discrepancies: not due to user structure issues, but caused by differences in event definitions and rules

Odaily Planet Daily reports that Uniswap founder Hayden Adams posted on X platform that the prediction market Kalshi prices the “U.S. acquisition of Greenland” at about 42%, while Polymarket prices it at only 15%–23%. Such a significant price discrepancy is not due to differences in user groups, but more related to the specific betting targets themselves. If it were just a matter of different user structures, a trader with access to both major platforms could quickly arbitrage away the price difference. However, the actual situation may be: Polymarket’s “probability of happening within 2026 (currently about 23%)” and Kalshi’s “probability of happening during Trump’s entire term (currently about 45%)” are not the same event. Additionally, differences in question phrasing, settlement conditions, oracle design, and risk pricing logic can all lead to different pricing.