The state-federal conflict over prediction market regulation intensified on Friday as New York Attorney General Letitia James joined a bipartisan coalition of 37 other attorneys general urging Massachusetts’ top court to uphold a preliminary injunction against Kalshi, while the CFTC simultaneously sued New York to block state enforcement against CFTC-registered exchanges, according to official statements and filings.
The amicus brief, filed in the Supreme Judicial Court of Massachusetts, asks the court to affirm a January ruling that Kalshi cannot offer sports event contracts to in-state residents without a Massachusetts Gaming Commission license. The coalition includes attorneys general from 37 states and the District of Columbia.
“Kalshi’s event contracts for sports are just illegal gambling by another name, and they should play by the same rules as every other licensed gambling platform,” James said in a statement.
According to the brief, Kalshi users wagered more than $1 billion every month on the platform in 2025, with sports betting accounting for roughly 90% of that volume in certain months. The coalition argues that Kalshi’s characterization of its contracts as “swaps” subject to exclusive CFTC oversight under Dodd-Frank misreads the 2010 statute, which the attorneys general say was crafted to address financial instruments behind the 2008 crisis, not to legalize sports gambling nationwide.
Hours later, the CFTC filed a complaint in the U.S. District Court for the Southern District of New York, naming James, Governor Kathy Hochul, the New York State Gaming Commission, Executive Director Robert Williams, and six commissioners as defendants.
The agency seeks a declaratory judgment that federal law grants it exclusive authority over event contracts, plus a permanent injunction blocking the state from enforcing what it calls preempted gambling laws against CFTC-registered entities.
“New York is the latest state to ignore federal law and decades of precedent by seeking to enforce state gambling laws against CFTC-registered exchanges,” CFTC Chairman Michael Selig said in a statement. The agency cited an October cease-and-desist letter Kalshi received from New York gaming regulators, alongside civil suits against Coinbase and Gemini filed this week, as conduct intruding on federal jurisdiction.
James and Hochul, both Democrats, issued a joint statement Friday evening accusing the Trump administration of “prioritizing big corporations over consumers and New Yorkers’ best interests” and pledging to defend the state’s gambling laws in court.
The CFTC’s New York complaint follows nearly identical suits the agency filed against Arizona, Connecticut, and Illinois on April 2. CFTC Chairman Selig has steadily expanded the agency’s jurisdictional posture since taking over, withdrawing a Biden-era proposal that would have banned political event contracts and warning state regulators in February that the agency would “no longer sit idly by.”
Court outcomes across states have been mixed. The U.S. Court of Appeals for the Third Circuit sided with Kalshi over New Jersey in a 2-1 ruling earlier this month, and a Tennessee federal judge granted the company a preliminary injunction in February. However, state and federal judges in Nevada, Maryland, Ohio, and Massachusetts have ruled against the platform.
Arizona, Connecticut, and Illinois—three states the CFTC is currently suing—all signed the Friday amicus brief, as did Tennessee and New Jersey, where federal courts have ruled in Kalshi’s favor. This breadth of signatories from states with different legal outcomes underscores how broadly state attorneys general view the preemption argument as a threat to traditional state authority over gambling.
The Friday actions cap a week of cascading enforcement. James sued Coinbase and Gemini on Tuesday, seeking a minimum of $2.2 billion and $1.2 billion, respectively. Wisconsin’s attorney general filed civil suits Thursday against Kalshi, Polymarket, Robinhood, Crypto.com, and Coinbase, alleging their sports event contracts violate the state’s commercial gambling ban.
Kalshi was last valued at roughly $22 billion following a $1 billion raise disclosed in March, and recorded over $10 billion in trading volume so far this month, according to The Block’s data. TD Cowen analyst Jaret Seiberg has said states still appear to hold the stronger legal position, with the dispute likely heading to the Supreme Court and a resolution potentially not arriving until 2028.