2026 US midterm elections: Prediction markets bet on Democratic Senate win; Republicans face a tough fight on the battlefield Today’s news
Prediction markets increasingly favor Democrats to take control of both houses of the U.S. Congress in Tuesday’s midterm elections, with Kalshi traders giving the party a 74% chance of winning the Senate and a 94% chance of securing the House as of noon ET Monday.
The odds suggest a strong shift in favor of Democrats as voters prepare to decide closely watched midterm races. Kalshi’s latest rating means the party’s probability of winning the Senate has increased by about 11 percentage points from about 63% on October 2.
On Polymarket, another major prediction platform, traders gave Democrats a 73% chance of winning the Senate, according to Benzinga.
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As of noon ET Monday, Kalshi gave Democrats a 74% chance of winning the Senate and a 94% chance of winning the House. Polymarket put its Senate rate at 73%.
Democrats need a net gain of four Senate seats to take control. In the lower house, they need a net gain of three mandates to reach the threshold of 218 seats.
Forecast market rates reflect trading activity and the prices participants are willing to pay for contracts on election results. They do not measure voter support and do not replace voting.
Polls cited in the article showed Democrats leading in Kansas, Maine, Ohio, Texas and narrowly in Alaska, while effectively tied with Republicans in Iowa. These contests could affect the balance of the Senate.
There is no single national result time; results will emerge state by state as officials count the ballots. You can follow updates through official state election websites and major news organizations such as AP, Reuters and The New York Times.
Prediction markets also indicated little expectation of a Republican victory in the House, with Kalshi traders putting the party’s chances at just 6%, compared to 94% for Democrats.
While the overall odds have changed little since Sunday, market forecasts are increasingly consolidating in favor of Democratic candidates in several competitive Senate races.
Democrats are gaining ground in key Senate battlegrounds
The latest market forecasting trends come as Democratic candidates appear to be making gains in several key Senate races.
The New York Times reported on Nov. 1 that its latest poll with the University of Siena showed Democrats leading in several battleground states, potentially boosting the party’s prospects for securing a Senate majority.
According to news reports, Democrats are ahead in five of the seven states that could determine control of the Senate. These include Kansas, Maine, Ohio and Texas, along with a narrow lead in Alaska. The party is effectively tied with Republicans in Iowa.
The polls are particularly significant because Democratic candidates lead in five states currently held by Republican senators and are effectively tied in a sixth.
Kalshi’s latest awards for some of the closely watched Senate contests also reflect the momentum.
As of noon ET Monday, the Democratic candidates had the following implied odds of winning:
– Michigan: Abdul El-Sayed had a 78% chance of beating Mike Rogers in an open seat currently held by Democrats.
– Maine: Troy Jackson had a 73% chance of defeating Republican Sen. Susan Collins.
– Ohio: Sherrod Brown had a 71% chance of defeating Republican Senator Jon Husted.
– Kansas: Adam Hamilton had a 63% chance of defeating Republican Sen. Roger Marshall.
– Iowa: Josh Turek had a 52% chance of defeating Republican Rep. Ashley Hinson.
How many seats do Democrats need to gain control of the Senate?
Republicans currently hold 53 seats in the Senate, while Democrats hold 47, including two independents running with them.
With 35 seats in the Senate heading into the midterm elections, Democrats need a net gain of four seats to secure control of the chamber.
The party must defend all seats it currently holds while flipping at least four Republican-held seats. A net gain of three would result in a 50-50 Senate, allowing Vice President J.D. Vance to cast the tie-breaking votes and maintain Republican control.
The challenge for Democrats was especially significant because several of the seats they need to flip are in traditionally Republican states.
However, the latest surveys and market trends suggest that the party may have a stronger opportunity than previously expected.
Read also | 2026 US Midterms: Can Democrats Flip 4 Republican Senate Seats?
Democrats have a stronger lead in House prediction markets
For House Democrats, the outlook appears to be even more favorable.
All 435 seats in the House are up for election in the midterms, and the party needs 218 seats to secure a majority.
Republicans currently hold a narrow majority after the 2024 election, winning 220 seats to Democrats’ 215.
Democrats therefore need a net gain of just three seats to control the House.
However, the most recent membership records kept by the Clerk of the House list 218 Republicans, 214 Democrats, one independent and two vacancies.
Unlike the Senate, where control could be determined by a handful of statewide contests, the outcome of the House will hinge on results in dozens of competitive congressional districts across the country.
Kalshi’s 94% probability of a Democratic House win suggests traders strongly expect a change in political control of the chamber.
Prediction markets are not the same as political polls
Despite the growing attention regarding election-related prediction markets, their odds should not be interpreted as conventional poll results.
Platforms like Kalshi and Polymarket operate differently from traditional political polls. Their prices reflect trading activity and participants’ willingness to buy and sell contracts based on expected election results.
As a result, forecast market probabilities are not substitutes for polling data and may not necessarily represent the true proportion of voters supporting a candidate or political party.
Nevertheless, the platforms have gained significant traction over the past year, thanks in part to the popularity of sports betting and the growing interest in event-based trading.
Election-related contracts also generated significant activity. A Bloomberg analysis of data from analytics platform Dune estimated that trade volume across Kalshi and Polymarket reached around $1.5 billion.
With the vote scheduled for Tuesday, traders are increasingly leaning toward a Democratic victory in both chambers, though the final outcome will depend on votes tallied across the country.
Read also | What the Midterm Campaign Tells Us About Where Our Politics Are Headed
