Baltimore sues Kalshi and Polymarket over sports bets

Baltimore filed separate consumer-protection lawsuits against Kalshi and Polymarket, accusing the firms of running illegal, unlicensed sports-betting platforms and misleading consumers about whether their products were lawful and properly regulated. The city says the offerings let residents wager on game winners, point spreads, point totals, player statistics and other propositions commonly sold by licensed sportsbooks.

The complaints say the platforms may call these transactions event contracts or prediction-market trades, but they function as sports bets under Maryland law. Baltimore also says neither company holds the sports-wagering contractor licence required by the Maryland Lottery and Gaming Control Agency.

Maryland regulation says a person without a valid sports-wagering contractor licence may not conduct, offer or operate sports-wagering contractor services for a licensed operator. The city argues that Kalshi and Polymarket have nonetheless made sports wagering available in Baltimore while avoiding the oversight, taxation, responsible-gambling requirements and consumer protections that apply to licensed sportsbooks.

The lawsuits also say the platforms have created a false or misleading impression that their offerings are lawful and properly supervised.

In the Kalshi case, Baltimore also named Robinhood Markets, Robinhood Derivatives, Webull Corporation, Webull Financial and Coinbase Financial Markets as defendants tied to the sports-wagering product. The city is seeking civil penalties, injunctive relief, restitution and disgorgement, with penalties of up to $1,000 per violation per day.

City Solicitor Ebony Thompson said Kalshi and Polymarket cannot circumvent Baltimore's consumer protections by repackaging gambling as something else or by claiming federal regulation puts them beyond the reach of local law. Mayor Brandon Scott said the city will not let multibillion-dollar companies put profits over people and harm communities through illegal gambling.

Kalshi said it is operating lawfully under the exclusive jurisdiction of its federal regulator and that the claims are already being addressed in federal court. The company said Maryland is litigating its sports contracts and that the matter is on appeal to the Fourth Circuit, and it called the new suit political theater.

The fight follows an earlier clash with Maryland regulators, who issued a cease-and-desist letter to Kalshi in April 2025 and said its contracts were indistinguishable from sports wagers. In August 2025, a federal judge denied Kalshi's bid for preliminary injunction relief and said Maryland's sports-wagering laws and the Commodity Exchange Act operate in tandem.

Polymarket said prediction markets on CFTC-registered exchanges are governed by federal law, not a patchwork of state and local rules. As reported in July, New York also sued Kalshi over similar allegations, a sign that the legal fight over prediction markets is widening.