Stew, a 35-year-old from Montana, has enjoyed dabbling in sports bets since he downloaded the Kalshi app about 18 months ago.
But just a few weeks ago, after spotting reports of elevated pizza deliveries around the Pentagon during some late-night scrolling, he made a different kind of bet - wagering $10 (£7.50) on the odds that Iran's Ayatollah Ali Khamenei would be "out" by 1 March.
It was a trade that tested the limits of the kinds of bets Americans are allowed to make.
So-called predictions markets - overseen by firms such as Kalshi - have exploded in popularity over the last year, hosting more than $44bn in trades.
They are rapidly transforming the betting landscape in the US, where sports betting was largely illegal until 2018 and gambling on elections had been off-limits for years until 2024.
