Before an Israeli strike during the Iran war’s opening days killed Iran’s Supreme Leader Ayatollah Ali Khamenei, a person trading under the account “Magamyman” made more than $553,000 placing bets on the Iran war and the end of Khamenei’s rule on Polymarket, which describes itself as the world’s biggest prediction market.

Prediction markets work by letting people bet on “event contracts” — wagers on whether something will occur, like an Oscar win, when Jesus Christ will return, and, in this case, the ousting of the late Iranian supreme leader by a certain date. The latter was quickly resolved through Khamenei’s death.

Betting on sports is not new, but anonymous bettors making huge profits off of war is an uncharted frontier. Polymarket currently has over 100 bets related to the Iran war, but recently balked at profiting off nuclear destruction and archived the bet “Nuclear weapon detonation by …?” Polymarket did not explain why or respond to HuffPost’s request for comment.

Federal commodity trading laws ban trades based on assassination and war, but Polymarket largely operates in an unregulated overseas exchange, doesn’t collect customer information, and only requires a cryptocurrency wallet to use.