Prediction markets on Polymarket and Kalshi favor Democrats winning both chambers of Congress in the 2026 U.S. midterm elections, assigning them probabilities of 78% and 74%, respectively. Trading volume in related Polymarket markets has exceeded $58 million, while trading volume in corresponding Kalshi contracts has topped $100 million. Both platforms also favor Democratic candidates in individual Senate races in Texas, Maine, and Michigan. Kalshi CEO Tarek Mansour said election-related betting volume in this election cycle has surpassed $1.4 billion. However, Kalshi previously failed to predict Luiz Inácio Lula da Silva's victory in the second round of Brazil's presidential election.