Ohio has announced its intention to fine the prediction market Kalshi over what it claims is illegal online gambling.

The state said April 14 that the fine is $5 million, which would be the largest ever state regulatory penalty for an online platform facilitating betting on sports.

In a notice to the company, Ohio claimed that Kalshi facilitates gambling to underage persons, including through alleged illegal advertising.

The state said that Kalshi advertising describes online gambling as a “side hustle” or “money hack.”

Recent U.S. surveys show growing problem sports betting behavior at the population level, fueled in part by misconceptions about winning money from gambling.

Kalshi ‘On Notice’ in Ohio

Ohio Attorney General Dave Yost said on social media platform X that the state put Kalshi “on notice” that its product is illegal gambling.

“Ohio put Kalshi on notice today that its ‘prediction markets’ are unlawful gaming and proposed a $5 million fine,” Yost said. “A federal court already agreed with our reading of the law. I wouldn’t bet on how long Kalshi will be operating in Ohio.”

Ohio isn’t the first state to call the betting platform predatory. Other states, including Michigan, Massachusetts, and New York, have said similar things about its product. Arizona filed criminal charges against the company.

“We are disappointed in this latest development, especially considering our ongoing litigation with Ohio and recent rulings in other courts confirming our right to operate as a federally licensed exchange. We are reviewing the Gaming Commission’s letter,” a spokesperson for Kalshi said in an email to The Columbus Dispatch.

The legality of prediction markets, which operate nearly nationwide under CFTC certification, could eventually reach the U.S. Supreme Court. These platforms allow stock-market-style betting on sports.

Ohio’s Fight With Betting

Alongside its fight against Kalshi, Ohio has taken steps to repeal its online sports betting law. Earlier this month, lawmakers unveiled legislation to establish stronger consumer protections. 

Ohio’s current regulation of online sports betting received a “D” grade from the Center for Addiction Science, Policy, and Research (CASPR).

Ohioans wagered $10.3 billion on sports in 2025, marking the third consecutive year of growth. Ohio consistently ranks among the top states nationwide by handle and revenue, competing with much larger legacy markets despite launching only in 2023.

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