William Hill says a first-time customer has wagered a staggering £37,000 on the outcome of the US election just days before the historic vote.
The mystery punter has backed Republican candidate Donald Trump to defeat Democrat Hillary Clinton when Americans go to the polls on Tuesday.
The man stands to win more than £60,000 if Trump wins an election that has been mired in unprecedented scandal and remains under the cloud of an investigation by the FBI.
The punter put down the wager at a William Hill branch in Nottingham on Thursday night.
He initially backed the controversial business mogul to the tune of £15,000 at odds of 7/4. Not happy with that huge lump sum, he decided to return to the shop to bet another £22,000 at the same odds.
Should Trump win the election, the punter stands to pocket £64,750.
A spokesman for William Hill said: "He came into the branch last evening, bet £15,000, then returned a little later to bet another £22,000.
"Both bets were at 7/4, for a possible profit of £64,750."