Prediction-market traders are increasingly pricing in a Democratic takeover of both chambers of Congress, with Polygon (POL)-based Polymarket putting the odds of a 2026 midterm sweep at a record 60% as Election Day approaches.

Prediction Markets Shift Ahead of 2026 Midterms

Market commentator The Kobeissi Letter highlighted the data, saying, "Just one year ago, there was a mere 22% chance of a Democrat sweep, with odds up 20 percentage points since the Iran War began. Election day is 47 days out."

Military action in Iran began in February. Although the strikes pushed oil prices higher, the stock market has remained resilient.

President Donald Trump is reportedly scheduled to meet with Gulf leaders next week to discuss the next phase of the Iran war.

Polymarket Puts Democratic Sweep Odds At 60%

Polymarket's "Balance of Power: 2026 Midterms" market currently gives Democrats a 60% implied probability of winning control of both the House and Senate. The market has recorded more than $12 million in trading volume.

Polymarket's 2026 midterm markets currently price in a 60% chance for the Democratic Party to control the Senate, compared with 42% for Republicans.

The House market shows Democrats at 90% and Republicans at 11%. The Senate market has recorded $5 million in trading volume, while the House market has seen roughly $11 million.

Republicans currently hold control of both the House and Senate, with the 2026 midterm elections set for Nov. 3.

The odds come as Trump's approval ratings have declined sharply, with some recent polls putting his overall approval at 32% to 34%.

Last month, former New Jersey Gov. Chris Christie (R) warned that Trump's falling approval ratings could prompt Republican candidates in competitive races to distance themselves from the president ahead of the 2026 midterm elections.