Politics 3 min read By Alice Ashford
Traders on Kalshi bet heavily on a Democratic sweep of Congress in midterms
Trading on the Kalshi platform on midterm races has topped $1.4 billion, with traders giving Democrats a 93% chance of winning the House and 73% chance of taking the Senate.
Traders on the prediction market Kalshi are betting heavily on Democrats to win control of Congress in the midterm elections, with the platform's midterm-related trading volume surpassing $1.4 billion as of Tuesday, according to data supplied to Fortune. On Kalshi, traders give Democrats a 93% chance of winning control of the House and a 73% chance of taking the Senate.
The largest single contract asks whether Republicans or Democrats will control Congress, and it has drawn $251 million in trading volume. A similar contract on which party will control the House has crossed $181 million. A separate market tracking all four possible combinations of House and Senate control has topped $112 million. The platform allows traders to wager on everything from sports to politics, and its midterm forecasts are attracting significant attention from political observers.
Closely watched races are also drawing large sums. The Los Angeles mayoral race, which will determine whether Democrat Karen Bass wins a second term, has drawn just shy of $110 million in trading volume. The Texas Senate race is nearing $100 million, with traders giving Democrat James Talarico a 71% chance of defeating Republican Ken Paxton.
Bets in Texas are less one-sided at the state level. Traders give incumbent Republican Greg Abbott a 65% chance of winning the gubernatorial contest, which has drawn $21 million in trading volume. His challenger, Gina Hinojosa, is seeking to give Texas its first Democratic governor since 1995.
The surge in midterm trading builds on the breakout moment prediction markets had in 2024, when traders on Kalshi and Polymarket favoured Donald Trump as the winner even as polls largely showed a toss-up. That outcome helped establish the platforms as closely watched political barometers. Their record has since shown setbacks. Last month, traders on Kalshi and Polymarket gave Flávio Bolsonaro, son of former Brazilian President Jair Bolsonaro, roughly an 80% chance of winning the presidential runoff against incumbent Lula da Silva, before the odds swung toward Lula as results came in.
In August, traders gave Francesca Hong roughly a 95% chance of winning Wisconsin's Democratic gubernatorial primary. David Crowley instead edged her out by less than half a percentage point. Polymarket later deleted a celebratory post touting Hong's odds, while Kalshi's founders defended the forecast with the reminder: «5% is not 0%.»
Source: fortune.com
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