US midterm elections: Prediction markets give Democrats a 74% chance of sweeping Congress

Democrats are gaining ground in prediction markets ahead of the November 3 midterm elections, with Kalshi traders increasingly expecting the party to take control of both chambers of Congress. The platform’s balance of power market puts the chance of a Democratic sweep at 74% and a Republican sweep is given just 6%. The latest movement comes as polls show Democrats leading in several key battleground states. The inputs are taken from an exclusive chart shared by Kalshi Traders.

These figures reflect what traders are betting on, not the results of traditional political polling.

What are Kalshi traders predicting for the 2026 midterms?

Kalshi’s Congress Balance of Power market gives Democrats a 74% chance of winning both the Senate and the House of Representatives. The market lists a Democratic sweep as the most likely outcome. A Republican Senate and Democratic House combination has a 22% chance, while a Republican sweep stands at 6%. A Democratic Senate with a Republican House is listed below 1%. The inputs are taken from an exclusive chart shared by Kalshi Traders.


The market also shows substantial trading activity, with more than $57 million in total volume displayed.

On a separate Kalshi contract asking who will control the Senate, traders put the Democrats’ chances at 74%. That is the highest level recorded for the party on the platform since the market opened.

Why are the odds moving in Democrats’ favour?

The shift follows a New York Times and Siena University poll showing Democrats ahead in several battleground states. That has strengthened the party’s path to a possible Senate majority, as per CNBC.

Kalshi’s Senate-control market has also seen a major change. Republicans had dominated the market after it opened in 2024, but the gap between the parties narrowed after US and Israeli strikes on Iran began on February 28. Republican control briefly climbed to 60% in July before the trend reversed in mid-September.

Separate Senate race markets have moved in the same direction. Kalshi traders raised the odds of a Democratic win in Texas to 74%, up from 68.4% in the previous 24 hours. On Polymarket, the Iowa Senate race moved from 42% to 50% for Democrats.

What do the prediction market figures mean?

The figures need to be read carefully. Kalshi’s 74% estimate for a Democratic sweep refers to the party winning both the House and Senate. Its separate 74% Senate-control figure refers only to the Senate race for control of that chamber. The balance-of-power market also lists a 22% chance of a Democratic House with a Republican Senate and a 6% chance of Republicans controlling both chambers. These prices can change as traders respond to new information.

Prediction markets are not traditional polls. Their odds reflect trading activity and should not be treated as a guaranteed result or a substitute for polling.