US midterm elections 2026: Latest predictions and odds from Polymarket

US midterm elections 2026 are getting closer and prediction markets are pointing to a major shift in the balance of power in Congress. Polymarket’s latest figures show traders giving Democrats a 93% chance of taking the House and a 63% chance of taking the Senate. These are market-implied odds, not election results or guarantees, and they can change as trading moves.

The latest numbers were updated on September 28, 2026, with 33 days remaining until the election. The House market had about $13 million in trading volume, while the Senate market had about $5 million, as per a report by Polymarket.

Democrats lead the House prediction market

The House is where Polymarket shows the biggest gap between the two parties.

Democrats are priced at a 93% chance of winning control of the House. The Republican side is at about 8%. Polymarket’s House market had more than $12 million in trading volume when the figures were recorded.

All 435 House seats will be contested in the midterms. The market is therefore tracking control of the entire chamber rather than one individual race.

The figures shown on Polymarket also put the projected House balance at 161 Republican seats and 274 Democratic seats on the September 28 update.

Senate race remains much closer

The Senate picture is different. Polymarket gives Democrats a 63% chance of taking control of the Senate, compared with the Republican outcome at roughly 38%. The Senate market had about $5 million in volume on the September 28 update.

The market is also tracking 35 Senate contests in 2026, including the regular elections and special elections.

Several individual races are drawing particular attention. Polymarket currently has Democrat Abdul El-Sayed at 72% in Michigan, James Talarico at 61% in Texas and Sherrod Brown at 59% in Ohio. In Maine, the Democratic candidate is at 59%, while Republican Roger Marshall is at 73% in Kansas.

Those numbers show why the Senate market remains closer than the House market. A relatively small group of competitive races could determine which party controls the chamber.

What does Polymarket predict for Congress?

Polymarket also has a separate balance-of-power market. Its latest figures put a Democratic sweep of both chambers at 63%. A Republican Senate with a Democratic House is listed at 29%, while a Republican sweep is at 8%.

These figures should be read as the current prices in a prediction market. They represent what traders are collectively pricing into the contracts at that moment. They are not a statement that the election outcome is already decided.

With the November 3 election approaching, the House and Senate markets will continue to move as new campaign developments, polling and other information affect trading.

Polymarket’s September 28 numbers show a much wider Democratic lead in its House market than in its Senate market, while the overall balance-of-power market gives the Democratic sweep outcome the highest price.

FAQs

What are Polymarket’s latest House odds?
Polymarket gives Democrats a 93% chance of taking the House in its September 28 market.

What are the latest Senate odds?
Democrats are at 63% to take the Senate, according to Polymarket’s September 28 figures.