With control of Congress at stake in the Nov. 3 U.S. midterm elections, political betting markets are pointing toward a potential Democratic victory in both chambers. As voters head to the polls to decide the balance of power in Washington, traders are placing their bets on whether Democrats can take control of the House of Representatives and the Senate from Republicans.
According to Kalshi, Democrats have a 94% chance of winning control of the House and a 72% chance of taking the Senate. PredictIt is showing a similar trend. As of Nov. 2, its market prices gave Democrats a 92% chance of winning the House and a 72% chance of securing the Senate.
These figures suggest that traders expect Democrats to make significant gains. However, political betting markets have not always accurately predicted congressional election outcomes, and their current projections should not be mistaken for guaranteed results.
The track record of political betting markets offers a mixed picture of their ability to forecast election results. In the 2022 midterm elections, betting markets largely favored Republicans to win the House and gave them a 67% chance of taking control of the Senate. Republicans won the House, but Democrats retained the Senate, showing that markets can get one part of an election right while missing another.
The markets performed better in the 2018 midterms, when they favored Democrats to win the House and Republicans to retain the Senate. Both predictions proved correct. A similar pattern emerged in 2010, when betting markets expected Republicans to take the House while Democrats held on to the Senate. The results matched those expectations.
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The 2006 midterms, however, provided another example of how predictions can fall short. Markets expected Democrats to win the House but favored Republicans to retain the Senate. Democrats won the House as anticipated and also took control of the Senate, overturning the market’s expectations. These outcomes suggest that betting markets can offer a useful indication of the political climate, but their forecasts are not always reliable, particularly in closely contested races.
Political betting has grown substantially since 2016, developing into a multibillion-dollar market in which traders buy and sell contracts linked to the outcomes of elections and other political events. During the 2020 U.S. presidential election, approximately $1 billion was traded across political betting markets. Betfair alone accounted for more than $630 million, highlighting the scale of interest in predicting political outcomes.
PredictIt’s growing user base also reflects the expansion of the sector. The platform had around 22,000 traders during the 2016 U.S. presidential election. That figure rose to 177,000 in November 2022, while the platform reported 400,000 users in 2025. Interest has continued to rise ahead of the 2026 midterms. According to a CNN report published Oct. 23, trading volume across prediction markets had surpassed $1.4 billion ahead of the elections.
The growing numbers show how political forecasting has moved beyond traditional polling and become a popular activity among traders seeking to profit from their expectations of election results.
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One reason prediction markets attract attention is their ability to react quickly to political developments. Unlike conventional opinion polls, which require surveys to be conducted and results to be compiled, market prices can change as traders respond to debates, campaign announcements and breaking political news.
The 2022 Pennsylvania Senate race offers an example of how quickly these expectations can shift. Republican candidate Mehmet Oz faced Democrat John Fetterman in a closely watched contest. Before a televised debate between the candidates, a contract tied to an Oz victory was trading at 53 cents. Following the debate, the price climbed as high as 66 cents as traders became more confident about his chances.
The movement indicated a shift in market sentiment in Oz’s favor. However, Fetterman ultimately won the election. The episode illustrates an important distinction: a rising contract price reflects changing trader expectations, not necessarily a candidate’s actual chances of winning. Market participants can react strongly to a single event and still reach the wrong conclusion about the final result.
Research also suggests that prediction markets can provide useful information, although their accuracy depends on the circumstances. A 2026 study by Joshua Clinton and TzuFeng Huang examined nearly 2,200 political betting markets across PredictIt, Kalshi, Polymarket and the Iowa Electronic Markets.
The researchers found that, in the 2024 U.S. presidential election, the market favorite won only 55% of the time when contracts were priced between 40 and 60 cents. These prices represented contests in which the markets indicated relatively uncertain outcomes. The findings suggest that traders can offer valuable signals about the direction of an election, but a candidate or party favored by the market is far from certain to win. In closely contested races, translating market expectations into a reliable prediction can be particularly difficult.
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For the 2026 midterms, the strong Democratic advantage reflected in House and Senate contracts therefore indicates current market sentiment rather than a definitive forecast of the final results.
The expansion of political betting has also brought increased regulatory scrutiny in the United States. In 2022, the Commodity Futures Trading Commission (CFTC) directed PredictIt to wind down its operations. The regulator also fined Polymarket $1.2 million over its event-based contracts.
The regulatory environment surrounding prediction markets has since evolved, with legal and policy questions continuing to shape how these platforms operate in the United States. As trading activity grows around major political events, the industry faces the challenge of balancing public interest in forecasting outcomes with regulatory requirements governing these contracts.
With the 2026 midterm elections underway, Democrats have a clear advantage in the projections offered by major betting platforms. Whether that confidence translates into victories in both chambers of Congress remains to be seen. For now, the markets are signaling a possible shift in Washington’s balance of power. The final verdict, however, will come from voters, not traders.