Midterm bets near $1.9 billion in prediction markets as Democrats lead Kalshi odds

Record betting on the midterms

Americans had wagered nearly $1.9 billion on the midterms by late Monday, 2 November, across more than 7,000 outcomes, according to a Washington Post analysis. The outcomes range from what a candidate will say in a particular campaign speech to the overall balance of power in Congress. More trades have been placed on these midterms than on any previous election cycle, yet the total still trails 2024, when more than $3.6 billion was bet on Polymarket alone on whether Donald Trump or Kamala Harris would win the presidency. Prediction markets burst onto the scene about four years ago and have since spread into American politics.

In these markets, traders buy contracts that pay $1 if an outcome occurs and nothing if it does not. Prices are set by supply and demand rather than by a bookmaker, so an unlikely result might cost 10 cents and a likelier one 90 cents. Traders can also place several bets on the same event in pursuit of a bigger payout.

Platforms and odds

Most of the money, about $1.3 billion, went through Kalshi, while Polymarket recorded about $600 million, according to the same analysis.

Kalshi1,300

Polymarket600

Kalshi

1300 $ million

Polymarket

600 $ million

Data from the article text

The two platforms usually offer similar odds on most questions. Kalshi gives Democrats a 93 percent chance of winning the House and a 74 percent chance of winning the Senate. Because several platforms operate and users are anonymized, nobody can know exactly how many people, or who, has placed bets on the midterms.

House93%

Senate74%

House

93 %

Senate

74 %

Data from the article text

Questions about who may bet

The scale of the market has prompted questions about who should be allowed to bet. Prediction markets are already subject to federal commodities regulation, and Kalshi has pushed for stronger federal rules to curb insider trading. This year Kalshi has barred several candidates from betting on their own races, including one House candidate in North Carolina. NPR has reported that many campaign consultants say they bet on races, including ones they work on. Congress has also adopted its own internal rules to bar conflicts of interest.

Economic strain in Wisconsin's third district

In Eau Claire, Wisconsin, Erin Klaus is closing Tangled Up in Hue, the handmade artisan market she has run downtown for 18 years, at the end of the year. Sales have fallen for two years, and she had been paying staff from her own pocket while working as executive director of Downtown Eau Claire Inc. She described the decision in stark terms:

“This is the first time it's out of my control to save my business.”

She listed tariffs, inflation, the cost of living and healthcare as pressures on local shoppers, and said the administration's messaging seemed to deny that people like her were feeling the strain. Tariffs had forced her to absorb the cost of the T-shirts she sold, healthcare subsidies on the Affordable Care Act marketplace were not extended, and a paid parking program downtown felt like the final straw. The seat is a toss-up. Republican incumbent Derrick Van Orden has stayed close to Trump and defended the administration's record, while Democratic challenger Rebecca Cooke is making a third run at the seat and appealing to working people, farmers and business owners.

What the result could mean for Trump

Senior Democrats, expecting a majority in at least one chamber, have telegraphed investigations into the administration's policies, its Cabinet and ICE, as well as dealings between officials and private companies. If Republicans lose Congress in the elections on Tuesday, 3 November, the rest of Trump's term would likely be taken up by Democratic-led probes into his administration and business dealings, possibly including another impeachment. Sen. Andy Kim, D-N.J., who has campaigned in Iowa, Georgia and Texas this fall, put the dynamic plainly:

“Everyone is thinking about him and the harm that he has done to them directly.”

If Republicans keep their majorities, Trump would emerge more powerful with a firmer grip on his party, which owes much of its success to his month-long rallies in mainly conservative states. Polling adds another layer. The POLITICO Poll has found for a year that half of Americans rank the cost of living among their top three issues, and Democrats hold a strong edge on affordability. Yet the same polling suggests voters demanding action could turn on a party split between competing priorities. Officials across Asia are starting to weigh the prospect of a new US president.