According to U.K.-based gambling company Betfair, one “punter” (as bettors are called in that part of the world) has placed an extraordinary bet of 1 million pounds ($1.3 million) on Joe Biden to win the election. The gamble is the biggest political bet ever placed on Betfair’s exchange and would return winnings of 1.54 million pounds ($2 million) should Biden beat President Trump to win the White House, given the 8/15 odds placed on the Democratic nominee at the time of the wager.

More than 271 million pounds ($350 million) and counting have been wagered on the 2020 presidential election on Betfair’s platform—already exceeding the 199 million pounds ($257 million) placed on the 2016 election and making this year’s contest the bookmaker’s “biggest betting event of all time,” it says.

This past weekend saw 14 million pounds’ ($18 million) worth of bets placed on Biden and 8 million pounds staked on Trump, who remains a 15/8 long shot to win reelection despite his odds having improved lately, according to Betfair. The current odds give Biden a 65% chance of winning the election.

“The big money is coming for Biden because people get more confident at the end of an election about the state of the market, and the big hitters enter,” according to political gambler and Betfair election expert Paul Krishnamurty.

While betting on political elections remains outlawed in the U.S., the presidential election has become a hugely popular betting market for those abroad in countries that do allow political wagering, such as the U.K. Betfair says it expects the total amount staked on the 2020 election to hit 400 million pounds ($517 million) on its platform—an unprecedented amount of betting interest that many attribute to Trump and his unique way of drawing attention to the American political process.

“That has to be the Trump effect,” Krishnamurty says of the increased interest in political wagering. “He’s changed the game.”