NFL backs New Jersey bid to challenge Kalshi in Supreme Court

The NFL filed a brief Wednesday supporting New Jersey officials who asked the U.S. Supreme Court to review the state’s dispute with Kalshi, a prediction-market company. The league cited concerns about game integrity and customer protection.

The petition was filed by New Jersey Attorney General Jennifer Davenport and interim gaming enforcement director Mary Jo Flaherty. It asks whether sports event contracts offered by companies such as Kalshi are subject to state gambling laws or federal oversight by the Commodity Futures Trading Commission.

The NFL urged the justices to examine whether contracts linked to sporting events can be classified as “swaps” under federal commodities law. The league said a ruling could clarify the authority of state and federal regulators.

The brief cited trading data showing that NFL-related contracts accounted for about $1.8 billion of the $3.3 billion traded across prediction markets on the first Sunday of the football season. It described some contracts as vulnerable to manipulation by a single participant.

The league’s filing gave examples including a player changing their performance, a coach altering a lineup or an official changing a call. “These bets, in the NFL’s view, pose the greatest threats to game integrity, because many can be manipulated by a single person, especially if known in advance,” the brief stated.

The NFL also raised concerns about what it called a lack of “sensible safeguards” from the CFTC for sports-related event contracts. It described federal control over sports betting regulation as a “major question” because states have traditionally regulated gambling.

Thirty-nine states and the District of Columbia filed a separate brief Wednesday supporting New Jersey’s petition. The filing described the dispute between state regulators and the CFTC as a “national turf war” over authority to regulate prediction markets.

“Waiting too long to address this issue will permit the federal-state regulatory dispute to escalate,” the states’ brief stated. The states asked the Supreme Court to resolve disagreements among lower courts, define the CFTC’s authority and clarify which laws apply to prediction-market companies.

The Supreme Court had not announced whether it would hear the case. Kalshi received additional time to respond to New Jersey’s petition and has until Nov. 9 to address questions about jurisdiction, the possible manipulation of event contracts and customer protection.

Kalshi has argued that it cannot be regulated by 50 separate state authorities. New Jersey’s case is part of broader state action involving prediction-market companies, including a lawsuit filed by New York against Polymarket over alleged illegal gambling.