Kalshi’s early midterm record puts election market accuracy in focus

Kalshi favorites prevailed in 479 of the first 487 midterm races decided, a 98 percent success rate, according to NextPredict. The tally offers an early measure of how market favorites performed against election results.

Kalshi CEO Tarek Mansour cited the 479-of-487 record in his post-election assessment of market accuracy, according to NextPredict. The figure covers the first races decided, rather than a complete accounting of all midterm contests.

Election trading clears a volume milestone

NextPredict’s weekly review, covering October 31 to November 6, said combined election-cycle volume on Kalshi and Polymarket topped 3 billion dollars.

That volume figure spans both platforms, while the reported favorites’ win record applies specifically to Kalshi. The summary does not provide separate volume totals for the two venues or a comparable accuracy tally for Polymarket.

What it means for prediction markets

• Scope matters: The 98 percent success rate describes Kalshi favorites in the first 487 races decided, not necessarily the full midterm slate.
• Winning favorites are one measure of accuracy: The summary does not supply the underlying contract probabilities, so the tally alone cannot establish how closely those probabilities matched outcomes.
• Volume and accuracy are distinct: Combined election-cycle trading above 3 billion dollars measures activity across Kalshi and Polymarket; it does not establish either platform’s forecasting performance.