Vice President Kamala Harris’ chances of winning Tuesday’s election have increased significantly in the final days of the race, according to a bookmaker.

Polymarket, an online platform that allows users to place “yes” or “no” bets on the likelihood of world events, currently gives the vice president a 41.4 percent chance of winning, with Donald Trump at 58.5 as of Monday morning percent is the favorite.

On October 30, Polymarket said Harris had a 33 percent chance of winning the 2024 election. Trump’s chances of winning have fallen nearly 10 points at the time of writing on Monday morning, compared to the 67 percent that Polymarket had the same day.

Polymarket is a betting platform based abroad. It works broadly like a stock market, allowing users to buy and sell shares that represent future events. This makes the odds improve or decrease depending on how much money is spent on a particular outcome, in this case who wins the presidential election. If you buy shares of Harris, who will win when she has a 41.4 percent chance of winning, and hold on to them until the election, you’ll get $1 for every 41 cents you invest – of course, only if the vice president actually wins.

Questions have arisen about Trump’s chances in Polymarket’s forecast as a person is said to be behind several accounts that have spent millions of dollars betting that Trump will win the race on Tuesday. The former president’s odds of winning were generally higher on the site than other forecasters.

Newsweek has emailed the Trump and Harris campaigns and Polymarket for comment.

Harris’ improved electoral chances on the site came after a surprise poll showed her beating Trump in Iowa, a state previously considered out of play for the Democrat.

The poll by J. Ann Selzer, one of the most respected and accurate pollsters, for Des Moines Register and Mediacom showed Harris leading in Iowa, 47 percent to 44. The result is within the margin of error of plus or minus 3.4 percentage points. The poll of 808 likely Iowa voters was conducted between Oct. 28 and Oct. 31.

Trump led Harris by 4 points (47 to 43) in a September Iowa poll. In a Selzer poll in June, Trump had an 18-point lead over President Joe Biden, then the presumptive Democratic nominee. Trump won Iowa in both the 2016 and 2020 elections by margins of nearly 10 and 9 points, respectively.

Although the Iowa poll is only a national poll, it could indicate that Harris is gaining significant momentum and support as the campaign winds down. Pollsters say a surprise Harris result in Iowa could have a bigger impact on the race nationwide.

“In a scenario where Harris wins Iowa, she is likely to do well elsewhere in the Midwest, particularly Michigan and Wisconsin. In that case, she would already be almost assured of victory in the Electoral College,” wrote veteran pollster Nate Silver on his Silver Bulletin blog.

Selzer pointed out that older women and self-employed women were largely responsible for the shift toward Harris in Iowa.

Older voters support Harris over Trump 63 percent to 28 percent.

Independent voters, who had previously supported Trump in every other Iowa Selzer poll this year, now favor Harris 46 percent to 39 percent. Independent women also now support Harris over Trump 57 percent to 29 percent, a significant increase from the vice president’s 5-point lead in the September poll (40 percent to 35).

An Emerson College poll of 800 likely Iowa voters, released the same day as the Selzer poll, suggests Tuesday’s election will be more closely aligned with previous results.

The poll gives Trump a 10-point lead over Harris in Iowa (53 percent to 43 percent). The poll was conducted on November 1st and 2nd and has a margin of error of plus or minus 3.4 percentage points.

As of this writing Monday morning, Polymarket estimates Harris has a 19 percent chance of winning Iowa on Tuesday, up from 5 percent the day before the Selzer poll was released.

In terms of the seven key swing states, Polymarket currently says Harris is the favorite in Wisconsin (59 percent chance of winning to Trump’s 42) and Michigan (61 percent to 40).

Polymarket gives Trump a better chance of winning in Arizona (77 to 25), Georgia (66 to 34), Nevada (63 to 37), North Carolina (66 to 35) and Pennsylvania (57 to 44).