OAKLAND — California Attorney General Rob Bonta today joined a coalition of 37 attorneys general in filing an amicus brief supporting Ohio’s right to enforce its state sports gaming and gambling laws against prediction market operator Kalshi. The amicus brief supports Ohio gaming authorities in KalshiEx LLC v. Schuler et al, which is pending in the U.S. Court of Appeals for the Sixth Circuit. Kalshi is currently appealing a federal district court's decision that denied the company's request for a preliminary injunction against the state. This filing marks the seventh time California has joined nationwide multistate amicus efforts targeting Kalshi and similar prediction market companies.

"This filing is representative of our bipartisan commitment to protecting state regulatory authority over illegal, unregulated gambling operations," said Attorney General Bonta. “Prediction markets cannot use federal loopholes to bypass state consumer protection, sports gaming, and gambling laws. By joining this brief, we are standing firmly with Ohio and our state partners to ensure that federal commodities laws are not weaponized to evade state laws, fuel gambling addiction, and undermine state revenue.”

The litigation stems from a lawsuit filed by Kalshi on October 7, 2025, which claimed that federal law preempted Ohio’s gaming regulations. On March 9, 2026, the U.S. District Court for the Southern District of Ohio rejected Kalshi’s arguments, ruling that the company's sports-event contracts are not "swaps" under the Commodities Exchange Act, and that Ohio’s gambling laws remain fully enforceable. Kalshi appealed the ruling the following day, and the Ohio gaming authorities subsequently fined Kalshi $5 million for illegal gambling. Just two weeks ago, California joined a nearly identical brief in the Sixth Circuit supporting Tennessee in a parallel matter. The Sixth Circuit has consolidated the cases, with oral arguments scheduled for July 30, 2026. 

Attorney General Bonta joins the attorneys general of Alabama, Alaska, Arizona, Arkansas, Colorado, Delaware, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Nebraska, New Jersey, New Mexico, New York, North Carolina, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, South Dakota, Vermont, Virginia, Washington, Wisconsin, and Wyoming in filing the brief. 

Here is a copy of the brief.