US Midterm Betting Surges Past 2024 Congressional Total

Wagering on the upcoming US midterm elections has already reached $133 million, exceeding the $92.4 million placed during the entire 2024 congressional election cycle, according to data released by the Anti-Corruption Data Collective (ACDC). The non-profit research group projects that total wagers could climb to $1.6 billion if current momentum continues.

The surge reflects the rapid expansion of prediction markets, with platforms like Polymarket and Kalshi attracting both retail and institutional users. These platforms allow betting on real-world outcomes, from political races to economic indicators and cultural events.

ACDC's analysis, covering 7,466 markets across three platforms through August 10, found that major platforms have opened 16 times more midterm markets compared to 2024. "Coverage has exploded compared to 2024. There are now multiple markets open for nearly every seat in the country," said Michelle Kendler-Kretsch, a research fellow at ACDC.

The growth has drawn regulatory scrutiny, with critics labeling the platforms as gambling operations. However, the companies and the Trump administration argue these are legitimate financial markets that allow users to hedge risks or trade on future-event views.

ACDC also highlighted concerns about market concentration, noting that the top 1% of digital wallets on Polymarket Global account for 68% of all trading volumes in 2026 congressional markets. David Szakonyi, ACDC's co-founder, warned that markets on outcomes like endorsements could enable insider trading and that prediction odds might undermine public trust in elections.

The findings come roughly three months before the November 3 midterm elections, with most state primaries running until mid-September. In 2024, Kalshi won a landmark legal case against the US Commodity Futures Trading Commission, clearing the way for Americans to use derivatives for event betting.