Nearly $1.9 billion had been traded on the 2026 U.S. midterm elections across Kalshi and Polymarket by 8 p.m. ET on Monday, Nov. 2, according to an analysis by The Washington Post. Kalshi accounted for about $1.3 billion, while Polymarket recorded roughly $600 million.
Both platforms’ odds favored Democrats to win control of Congress. Polymarket put the party’s chances of winning the Senate at 78% and flipping the House at 95%. Kalshi also assigned Democrats a 78% chance in the Senate, while giving them a 93.9% chance of taking the House.
Prediction markets let users trade “yes” or “no” contracts tied to possible election outcomes and other scenarios. Kalshi and Polymarket both prohibit insider trading. Polymarket recently said it had investigated dozens of midterm-related trades over concerns involving insider trading and manipulation, NPR reported.
The trading total remains below spending on campaign advertising: candidates are expected to spend about $3.9 billion on ads across House and Senate races, according to a New York Times analysis of AdImpact data. It is also well below the more than $3.6 billion wagered on Polymarket alone on the 2024 presidential contest between Donald Trump and Kamala Harris, according to The Washington Post.
Sources: Variety.