New Delhi, March 2 -- As bombs fell in the middle east this weekend, traders on prediction markets such as Polymarket and Kalshi saw windfall gains on bets ranging from the date of the United States attack to the killing of Iran's Supreme Leader Ayatollah Ali Khamenei.

Trades on Polymarket reached $529 million, while Kalshi recorded $36 million in bets regarding a regime change in Iran following the death of Khamenei. Analysts at Bubblemaps SA found that six accounts made roughly $1 million in profits by betting on the exact date of the attack, 28 February.

Analytics firm Polysights said contracts tied to the potential overthrow of Iran's supreme leader implied a 40% likelihood, but its data showed that 90% of accounts flagged for alleg...