Kalshi, the U.S.‑based regulated prediction‑market exchange, reported $4.15 billion in notional trading volume on Tuesday, Nov. 3, the day of the 2026 midterm elections. The figure marks the platform’s busiest weekday since it began publishing daily data, yet it remains well below the $5.3 billion record set on Saturday, Oct. 24, and the $4.79 billion logged on Oct. 31. The surge reflects heightened interest in the election outcomes, but the composition of that activity shifted markedly from earlier record‑setting days.

Shift From Combo to Single‑Market Contracts

Kalshi’s “combo” contracts—parlay‑style bundles that combine several outcomes—accounted for $2.43 billion, or 58.6% of the day’s volume. That share dropped sharply from 75.5% on Oct. 24 and 73.9% on Oct. 31, representing the lowest combo proportion since at least Oct. 10, according to the exchange’s daily market data. By contrast, single‑market contracts rose to $1.72 billion, roughly a third higher than the $1.30 billion recorded on Oct. 24 and the strongest single‑market figure in the same period. The data suggest traders favored straightforward bets on individual races rather than the higher‑risk, low‑price combos that had driven earlier spikes.

Top Election Series and Bitcoin Contracts

The five most active election series—Texas Senate, House control, Texas governor, Senate control, and a combined balance‑of‑power market—collectively generated about $440 million in volume. Texas’s Senate race led with $108.1 million, followed closely by the House‑control market at $99.8 million and the Texas governor race at $88.6 million. Notably, Kalshi’s 15‑minute Bitcoin contracts outperformed any single election series, trading $332.6 million on Election Day. Over their lifetimes, Kalshi’s Democrat‑winning contracts for the House and Senate have settled over 49 million and 32 million contracts respectively, underscoring the platform’s role in political forecasting.

Potential Regulatory Fallout

Both Kalshi and rival Polymarket settled their Senate‑control and House‑control markets in favor of Democrats shortly after the polls closed, aligning with the platforms’ pre‑election forecasts. The outcomes arrive as lawmakers from both parties advance legislation targeting prediction markets, including the “Prediction Markets Are Gambling Act” introduced by Sens. Adam Schiff and John Curtis. Experts cited by Front Office Sports warn that a Democratic‑controlled Congress could summon Kalshi and Polymarket to hearings and embed restrictions in spending bills, potentially curbing the CFTC’s authority over such platforms. Any legislative constraints would still require a presidential signature, and President Donald Trump’s stance could influence the final outcome.