Polymarket, election betting Watch Trump get past Harris

Topline

Former President Donald Trump is on the rise on gambling sites as more states close their polls, reversing the shrinking lead over Vice President Kamala Harris in betting odds after the first major polls closed, while survey-based prediction models showed the candidates were stuck in An dead heat on the way to election day.

Voters cast their ballots in Denver on Election Day, Tuesday, November 5, 2024.

Key facts

Polymarkt: Perhaps the most famous election betting player, the blockchain-based site still leaned Trump after the initial closes, giving him an implied 79% victory probability compared to Harris’ 22% as of about 9:30 PM EST.

Kalshi: The New York-based prediction platform favors Trump by a margin of 74% to 26%, a big shift from Saturday, when Harris led briefly on the site; Unlike Polymarket, Kalshi operates legally in the US, as do rival PredictIt and brokers Robinhood and Interactive Brokers.

Predict it: The site most heavily leaning toward Harris still favored Trump just after 9:30 p.m., with PredictIt prices ranging from 74% to 27% for Trump.

Robinhood/Interactive real estate agents: The retail giant is the newest major newcomer in the election betting space – and, like Interactive Brokers, offers election betting via ForecastEx – and gives Trump a winning chance of about 79%, compared to 25% for his Democratic opponent.

Honestly And Markets: The London-based sites are not open to Americans, but both offer similar odds for a Trump victory, with Betfair favoring Republicans by a 75% to 26% margin and Smarkets by a 75% to 26% tilt.

The odds around the time the first major polls closed at 6pm EST were around 60% for Trump and 40% for Harris on high-profile betting platforms.

Big number

74.1%. Those are the betting market’s aggregate odds for a Trump victory, according to the Election betting tool, which tracks odds from Betfair, Kalshi, PredictIt, Polymarket and Smarkets.

What do other indicators say?

When more polls closed at 9 p.m. EST, Trump had won 120 Electoral College votes, while Harris had 99, according to the Associated press. The New York Times live presidential prediction leaned slightly toward Trump, putting the race just outside the tossup category. Forbes provides live updates on the election results here.

In return for

Polling data to suggest Harris and Trump are on virtually equal footing on Election Day. FiveThirtyEight‘s predictions favor Harris by a 50% to 49% clip, while Silver Bulletinstatistician and Polymarket advisor Nate Silver’s model, leans toward Harris by a minuscule margin of 50.02% to 49.99%. The difference between betting market odds and poll-based prediction models has been a major topic of discussion in recent weeks suggestive Betting markets are a better predictor because gamblers are financially incentivized to bet on the candidate who is more likely to win and skeptics pointing to the potentially pro-Trump demographics among gamblers as an explanation for the skew.

What do the betting odds show for control of the Senate and House of Representatives?

Currently, Democrats control the Senate with 51 seats, compared to Republicans’ 49, and Republicans control the House. The Election betting tool, which aggregates odds from multiple sites, leans heavily toward Republicans taking control of the Senate from Democrats by a margin of 87% to 13% as of 8:35 PM EST. The same place favors Republicans taking control of the House of Representatives by a margin of 52% to 49%.

How do election bets work?

Sites offer users contracts whose prices are tied to a given candidate’s real-time, market-implied probabilities. Each contract pays out $1 if the bettor chose the winning candidate and $0 if his bet was incorrect. So at current expectations, a contract for Trump would cost about $0.57 and a contract for Harris would cost about $0.44 for Robinhood, with the same binary return of $0 or $1 for each contract. Election betting sites operating legally in the US have comparative limits, with Robinhood allowing 5,000 contracts per user and PredictIt allowing $850 per user on each election market.

When are election bets settled?

It varies per platform. Polymarket’s main market will pay out when the Associated Press, Fox News and NBC News bureaus all call the election in favor of one candidate (so possibly as early as this week). Robinhood will pay winning bettors on January 7, the day after Congress certifies the results, Kalshi on Inauguration Day on January 20, and PredictIt says it will pay out if “any ambiguity or uncertainty occurs before the market is resolved.”

CORRECTION (5/11): This story has been updated to reflect that Interactive Brokers and Robinhood go to the same exchange and cannot have different odds.