California joins New York and Wisconsin in two new court battles against Kalshi as states fight to enforce gambling laws
Sacramento, California – California’s latest fight over online sports wagering is playing out in courtrooms far from home. Attorney General Rob Bonta has again backed states seeking to enforce their gambling laws against Kalshi, bringing California’s participation in multistate court filings involving prediction market companies to 11.
The two newest filings support New York and Wisconsin. At their center is a question with consequences beyond either state: whether federal commodities law prevents states from applying their own gambling rules to sports-event contracts.
Bonta joined bipartisan coalitions of attorneys general last week in submitting amicus briefs, which offer courts arguments from parties outside the litigation. The coalitions argue that allowing prediction market operators to bypass state gambling laws would weaken states’ traditional oversight and their ability to protect vulnerable residents.
“Prediction markets cannot use federal loopholes to bypass state consumer protection, sports gaming, and gambling laws,” Bonta said.
He also raised concerns about young people and gambling addiction, describing the filings as a shared commitment across party lines to defend state regulatory authority.
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The New York dispute began after the New York State Gaming Commission issued Kalshi a cease-and-desist order. Kalshi sued the commission and sought a preliminary injunction to prevent enforcement.
The district court denied that request, holding that federal law did not preempt New York’s gambling laws as applied to Kalshi’s sports-event contracts. Kalshi appealed to the U.S. Court of Appeals for the Second Circuit, where the attorneys general filed their brief supporting New York.
Wisconsin’s case followed a different route. The state brought enforcement actions in state court against Coinbase, Kalshi, Robinhood, Polymarket and Crypto.com. After the companies moved the cases to federal court, the Commodity Futures Trading Commission filed its own federal lawsuit against Wisconsin.
The federal regulator also sought a preliminary injunction blocking Wisconsin from enforcing its gambling laws. The district court denied that request, and the CFTC appealed to the U.S. Court of Appeals for the Seventh Circuit. The coalition’s Wisconsin brief supports the state’s authority to continue enforcement.
For Bonta, these filings extend an existing legal effort. They mark California’s tenth and eleventh appearances in multistate amicus efforts targeting Kalshi and similar companies, with both appeals now carrying the broader dispute over who regulates these offerings.
