A King County Superior Court judge granted Washington a preliminary injunction on Monday after finding Kalshi likely violated the state’s Gambling Act and Consumer Protection Act by running an illegal gambling operation in Washington. The court said it will issue a final order on Aug. 5, after Kalshi and the attorney general’s office confer on the terms of the injunction and file more briefing on remedies.
The attorney general’s office said the ruling was the first step toward holding Kalshi accountable for what Attorney General Nick Brown called “brazen violations of Washington law.” The lawsuit, filed in March, says the company operated and advertised an online platform where users could bet on sports, elections and other events, and asks the court to stop the activity, recover money lost by Washingtonians and impose civil penalties.
According to the state, Kalshi entered the betting market in 2025 and initially allowed Washington consumers to bet on college and professional sports. The complaint says the service offers spread bets, over/under bets and proposition bets, all of which are forms of wagering tied to the outcome of games or specific in-game events.
Kalshi has described itself as a federally regulated prediction market rather than a gambling site. Its website and app show consumers events to bet on and odds that determine payouts, and the company has advertised that it lets people “bet on anything.”
The state said one Kalshi advertisement, featuring a text exchange about betting on the NFL in Washington, suggested the company knew it was skirting state law. The court ruled that Kalshi’s provision, marketing and advertising of the service were unfair and deceptive acts or practices, and found Washington had shown both a likely win on the merits and a risk of substantial injury to consumers if no injunction issued.
The case also turned on Washington’s gambling rules. The attorney general’s office said state law defines gambling as staking or risking something of value on the outcome of a contest of chance or a future contingent event, and that a 2006 amendment to the 1973 Gambling Act made clear that internet gambling is prohibited. The state said gambling remains tightly regulated to protect the public.
Kalshi has said states do not have jurisdiction to regulate prediction markets. KUOW reported that Judge John McHale rejected the view that federal oversight pre-empts Washington’s gambling laws, while Kalshi has argued that the Commodity Exchange Act shields its online markets from state regulation.
The broader fight has spread beyond Washington. KUOW reported that the state joins Massachusetts, Michigan, Nevada and New York in suing to restrict Kalshi under state online-gambling laws. The judge’s written order said the public interest and the potential harm to consumers outweighed any harm to Kalshi if the platform were halted in Washington.
