Polymarket gives Democrats 90% odds for the House, 60% for Senate

Democrats are now favored to retake both chambers of Congress, but the market sees the House and Senate as very different fights. Polymarket puts Democrats at 90% to win the House and 60% to win the Senate, with the combined chance of flipping both chambers reaching a reported record 60%.

Polymarket’s new 2026 Midterms Hub turns those shifting expectations into continuously updated odds for major Senate and House races. The snapshot released September 18 shows the party’s Senate odds at 60% and its House odds at 90%.