Former President Donald Trump has been surging on betting sites as more states close their polls, turning around what had been a shrinking lead over Vice President Kamala Harris in betting odds after the first major polls closed, while survey-based prediction models indicated the candidates were locked in a dead heat heading into Election Day.
Voters cast their ballots in Denver on Election Day, Tuesday, Nov. 5, 2024.
Polymarket: Perhaps the most famous election betting player, the blockchain-based site still leaned toward Trump after the first closures, giving him 88% implied odds of victory compared to Harris’ 10% as of about 10:10 p.m. EST.
Kalshi: The New York-based prediction platform favors Trump by a 84% to 16% margin, a major shift from Saturday, when Harris briefly led on the site; unlike Polymarket, Kalshi legally operates in the U.S., as do rival PredictIt and brokerages Robinhood and Interactive Brokers.
PredictIt: The site tilting most strongly toward Harris still favored Trump at 10 p.m., with PredictIt pricing at 86% to 15% for Trump.
Robinhood/Interactive Brokers: The retail trading giant is the newest major entrant into election betting—and, like Interactive Brokers, offers election betting via ForecastEx—and gives Trump about a 90% win probability compared to 15% for his Democratic opponent.
Betfair and Smarkets: The London-based sites are not open to Americans, but both assign similar chances of a Trump win, with Betfair favoring the Republican by a 88% to 14% margin and Smarkets by a 88% to 12% tilt.
Odds around the time of the first major poll closures at 6 p.m. EST were roughly 60% for Trump and 40% for Harris on high-profile betting platforms.
87.3%. That’s the betting market’s aggregated odds for a Trump victory, according to the Election Betting Odds tool, which tracks odds across Betfair, Kalshi, PredictIt, Polymarket and Smarkets.
As of 10:15 p.m. EST, Trump had secured 198 Electoral College votes while Harris had 109, according to the Associated Press. The New York Times live presidential forecast leaned toward Trump and showed him with a 78% chance of victory. Forbes is providing live updates on election results here.
Polling data suggest almost Harris and Trump stand on nearly equal footing on Election Day. FiveThirtyEight’s forecasts favor Harris at a 50% to 49% clip, while Silver Bulletin, the model run by statistician and Polymarket advisor Nate Silver, leans toward Harris by a miniscule 50.02% to 49.99% margin. The difference between betting market odds and poll-based prediction models has been a major subject of debate in recent weeks, with some suggesting betting markets are a better predictor as bettors are financially incentivized to wager on the candidate more likely to win and skeptics pointing to the potentially pro-Trump demographic among bettors as an explanation for the skew.
Currently, Democrats have control of the Senate with 51 seats compared to the Republicans’ 49, and Republicans have control of the House. The Election Betting Odds tool, which compiles odds from multiple sites, leans heavily toward Republicans taking control of the Senate from Democrats by a margin of 96% to 4% as of 10 p.m. EST. The same site favors Republicans to take control of the House by a 68% to 32% margin.
Sites offer users contracts whose prices are tied to the real-time, market-implied odds of a certain candidate. Each contract pays out $1 if the bettor opted for the winning candidate and $0 if their wager was incorrect. So at the current odds, a contract for Trump would cost about $0.57 and one for Harris roughly $0.44 on Robinhood, with the same binary $0 or $1 return offered for each contract. Election betting sites which operate legally in the U.S. have comparative limits, with Robinhood allowing 5,000 contracts per user and PredictIt $850 per user on each election market.
It varies by platform. Polymarket’s main market will pay out when the Associated Press, Fox News and NBC News desks all call the election in one candidate’s favor (so potentially as soon as this week), Robinhood will pay winning bettors Jan. 7, the day after Congress certifies results, Kalshi on the day of the Jan. 20 inauguration and PredictIt says it will pay out when “any ambiguity or uncertainty before the market is settled.”
CORRECTION (11/5): This story has been updated to reflect that Interactive Brokers and Robinhood route to the same exchange and cannot have different odds.