Ayatollah Ali Khamenei was not, it’s safe to assume, a devoted Polymarket user. If he had been, the Iranian leader might still be alive. Hours before Khamenei’s compound in Tehran was reduced to rubble last week, an account under the username “magamyman” bet about $20,000 that the supreme leader would no longer be in power by the end of March. Polymarket placed the odds at just 14 percent, netting “magamyman” a profit of more than $120,000. Everyone knew that an attack might be in the works—