Ohio’s marquee races draw more than $10 million on Kalshi

Ohio’s two highest-profile statewide contests had drawn more than $10 million in trading on Kalshi ahead of the Nov. 3 election. More than $7.3 million had been wagered on the Senate contest between Jon Husted and Sherrod Brown as of Oct. 16, while the governor’s race between Vivek Ramaswamy and Amy Acton had attracted more than $2.7 million.

The Senate race ranked among the most-traded political events on Kalshi’s Midterms Hub. Brown and Acton were favored on both Kalshi and Polymarket at the time, meaning traders could earn greater returns by correctly backing Husted or Ramaswamy.

The activity adds to a broader expansion in political contracts. As covered earlier this month, trading on this year’s congressional midterm markets had already exceeded the total recorded across the 2024 cycle. Kalshi and Polymarket also offered contracts on down-ballot races, county-level outcomes, victory margins and the proposed Ohio constitutional amendment that would require photo identification at the polls.

Prediction markets gained particular attention after they forecast Donald Trump’s 2024 victory while many polls showed a close contest. Supporters argue that the markets aggregate the judgment of participants who have a financial reason to make accurate calls, while polls are snapshots rather than tools designed to predict results.

Their record is mixed. Rajiv Sethi said the markets missed U.S. House races in 2024 despite correctly calling Trump’s win, and they heavily favored a Wisconsin gubernatorial candidate who lost the Democratic primary in August. A Washington Post analysis, however, found that most candidates priced at 70% to 80% in 2026 primaries went on to win.

The expanding Ohio market has coincided with a state fight over whether the platforms constitute gambling. The Sixth Circuit Court of Appeals unanimously ruled that Ohio could regulate prediction markets as it regulates the gambling industry, and Kalshi sought a rehearing before the full court. Kalshi and other operators maintain that their model differs fundamentally from gambling, while Gov. Mike DeWine said the advertising made clear to him that it was betting and gambling.

State Sen. Bill DeMora has introduced Senate Bill 479, which would prohibit election betting and bar platforms from offering election-related contracts. A separate measure, Senate Bill 430, would classify sporting-event contracts as sports gambling subject to state regulation and taxation.

Both bills were awaiting sponsor testimony in their respective committees, according to DeMora’s office. DeMora said election contracts could undermine trust by encouraging suspicions that a heavily backed candidate’s victory had been fixed, while critics have also raised insider-trading concerns after Kalshi suspended three congressional candidates for betting on their own races earlier this year.