KALSHI VS POLYMARKET: GREENLAND SPREAD ISN'T FREE MONEY

Summary from the TLDR Crypto newsletter

Kalshi estimates a US acquisition of Greenland during Trump's term at roughly 42-45% while Polymarket prices a 2026-specific outcome at ~15–23%. The apparent arbitrage is largely explained by different contract phrasing, settlement windows, and oracle/condition differences. This means a trader eligible to trade in both markets could narrow obvious gaps, but persistent spreads can remain rational once the markets are compared on identical terms.