Robert Prevost, a 100-1 long shot, unexpectedly won the papal election, becoming Pope Leo XIV. Prevost, previously unknown in betting markets, stunned bookmakers and prediction market bettors. While betting on the papacy isn't legal in the US, some bettors on Kalshi and Polymarket won large sums on Prevost's victory. Favorites like Parolin and Tagle were heavily favored, highlighting the unpredictability of the papal election. Prevost's election also resulted in losses for bettors who wagered on the number of voting rounds and the age of the new pope.

Prepared by Emily Rhodes and reviewed by editorial team.