Massachusetts judge lets state amend sports betting lawsuit against Kalshi after ruling

Kalshi’s fight with Massachusetts is not going away: a Suffolk County Superior Court judge allowed state authorities to file a 71-page amended complaint accusing the prediction markets platform of running unlicensed sports wagering. For high-risk operators, the practical point is simple — if a product looks like sports betting, state regulators will try to treat it like sports betting, even when the company says it is offering event contracts.

1. In a Tuesday filing, associate justice Peter Krupp allowed Massachusetts authorities to add allegations to their case against Kalshi. The amended complaint builds on the state’s claim that Kalshi engaged in sports wagering in violation of state laws.
2. The new filing says Kalshi “targets those under 21 years of age and does little to stop them from using its platform,” pointing to marketing on university campuses and ads showing people who “appear to be younger than 21 years old.” Massachusetts also alleged that Kalshi allows anyone who is at least 18 years old to create an account and wager on sports events by purchasing event contracts.
3. Massachusetts Attorney General Andrea Joy Campbell first announced the lawsuit in September 2025, arguing that Kalshi needed a license from the Massachusetts Gaming Commission to comply with state laws on online sports wagers. In January, a judge granted a preliminary injunction blocking Kalshi from offering sports event contracts while the case is under review.
4. The case sits inside a wider fight between prediction markets firms like Kalshi and Polymarket and state-level authorities. These platforms let users trade event contracts tied to outcomes in sports, politics and current events, which is exactly why regulators keep asking whether they are markets or sportsbooks with a different label.
5. Kalshi does have backing from the US Commodity Futures Trading Commission (CFTC), which filed a brief in Massachusetts in April saying the agency has “exclusive jurisdiction” over prediction markets. The CFTC, under Chair Michael Selig, has argued that event contracts on these platforms are “swaps” under the Commodity Exchange Act and therefore not subject to state regulation.

Congress is also being pulled into the dispute. Some gaming and tribal organizations and labor groups have called on US senators to address prediction markets through the CLARITY Act, and the underlying state-versus-federal argument is the kind that can keep climbing until a higher court, possibly even the US Supreme Court, gets involved.