Trading volume on US midterm election prediction markets has already exceeded the total for the 2024 cycle, with platforms like Kalshi and Polymarket seeing rapid growth and increased regulatory attention before November's elections
Trading activity tied to the 2026 US midterm elections has already surpassed the total volume seen during the entire 2024 congressional cycle, signaling a sharp expansion in the prediction market sector ahead of November’s vote. According to the Anti-Corruption Data Collective (ACDC), a non-profit research group, $133 million had been wagered on House and Senate outcomes as of August 10, 2026. This figure is well above the $92.4 million recorded for the 2024 cycle, based on data reported by Reuters.
Market Growth and Platform Expansion
ACDC’s analysis covered 7,466 markets across Kalshi, Polymarket, and Polymarket US, revealing that the number of available markets for the 2026 elections is 16 times higher than in 2024. Nearly every congressional seat now has multiple active markets, reflecting a surge in both retail and institutional participation. The group estimates that if current trends continue, total trading volume could reach $1.6 billion by the end of the 2026 midterm cycle.
Regulatory Scrutiny and Legal Developments
The rapid expansion of prediction markets has drawn increased attention from regulators. Critics argue that these platforms function as gambling operations, while companies and some policymakers maintain they are financial markets offering risk-hedging tools. In 2024, Kalshi secured a legal victory against the US Commodity Futures Trading Commission (CFTC), allowing Americans to trade derivatives linked to election outcomes. However, the sector remains under close regulatory observation, and the debate over classification continues.
Concentration and Market Risks
ACDC’s data also highlights a concentration of trading among a small group of users. On Polymarket Global, the top 1% of digital wallets accounted for 68% of trading volume in 2026 congressional markets. The group has raised concerns about the proliferation of markets tied to events such as political endorsements and speeches, warning that these could create opportunities for individuals with inside information. There are also questions about the potential impact of prediction market odds on public trust in election outcomes, especially if market expectations diverge from actual results.
Prediction markets allow users to buy and sell contracts based on the outcome of real-world events, including political races. Unlike traditional sportsbooks, these platforms often operate under different regulatory frameworks, with oversight from agencies like the CFTC rather than state gaming regulators. The distinction between event contracts and gambling remains a central issue for both policymakers and market participants, affecting how these products are regulated and accessed by US players.
