In the early hours of 13 June, more than 200 Israeli fighter jets began pummeling Iran with bombs, lighting up the Tehran skyline and initiating a 12-day war that would leave hundreds dead.

But for one user of the prediction market Polymarket, it was their lucky day. In the 24 hours before the strike occurred, they had bet tens of thousands of dollars on “yes” on the market “Israel military action against Iran by Friday?” when the prospect still seemed unlikely and odds were hovering at about 10%. After the strike, Polymarket declared that military action had been taken, and paid the user $128,000 for their lucky wager.

But was it just luck?

The Guardian’s analysis of blockchain data traced the wallet to an X account with its location set to Beit Ha’shita, a kibbutz in northern Israel. The user recently transferred their bets to two other accounts, data shows, potentially to avoid detection. There, they currently have 10 live bets relating to Israel’s military strategy.

The X user behind the account could not be reached for comment but Israel Defense Forces and the Israel Security Agency have opened an investigation into the user, officials said last Thursday.