NFL Backs New Jersey in Supreme Court Petition Against Prediction Market Platform Kalshi

NFL supports New Jersey's request for Supreme Court review

The NFL filed a legal brief with the US Supreme Court on Wednesday, backing New Jersey officials who want the court to review its case against prediction market platform Kalshi. The filing asks the justices to decide whether prediction markets fall under state authority or federal regulators.

New Jersey Attorney General Jennifer Davenport and gaming enforcement interim director Mary Jo Flaherty originally petitioned the Supreme Court. The NFL joined them through an amicus brief, which is a legal document filed by someone not directly involved in the case but with a strong interest in the outcome.

Key concerns raised by the NFL

• The league argued that sporting event contracts on prediction markets are "highly susceptible to manipulation" and threaten game integrity.
• On the first Sunday of the football season, about $1.8 billion of the $3.3 billion in trading volume on prediction markets was related to the NFL, according to league data cited in the filing.
• The NFL stated that a single person could potentially manipulate outcomes, such as a player altering their performance, a coach changing their lineup, or an official making or not making certain calls.
• The league called for the case to be reviewed to protect customers and address how sporting-event contracts are classified as "swaps" under current regulation.

What the NFL brief says about manipulation risks

The amicus brief described specific scenarios where bets could be manipulated. It noted that contracts on Kalshi and other platforms lack what the league called "sensible safeguards" from the Commodity Futures Trading Commission (CFTC), the federal agency that oversees commodity and derivatives markets.

The NFL argued that federalizing sports betting regulation, rather than leaving it to individual states, is a major question the Supreme Court should consider.

Thirty-nine states join the push

On the same day as the NFL filing, 39 US states and the District of Columbia submitted their own amicus brief supporting New Jersey's position. They described the conflict between the CFTC and state authorities as a "national turf war" that requires Supreme Court intervention.

The filing warned that waiting too long could allow the federal-state regulatory dispute to escalate. The states asked the Court to resolve a split among lower courts, clarify the CFTC's authority, and provide guidance on which laws apply.

Kalshi's response timeline

Kalshi was granted an extension to respond to the New Jersey filing. The company now has until November 9 to address issues related to jurisdiction, manipulable event contracts, and consumer protection.

A Kalshi spokesperson told Cointelegraph after the September filing that the company could not be "regulated by 50 different regulators." This refers to the challenge prediction market companies face when each state could potentially enforce its own rules.

Supreme Court has not yet decided

As of Thursday, the Supreme Court had not announced whether it would agree to hear the case. While New Jersey was the first to petition the court, other state-level actions against prediction market companies could also face appeals.

Why this matters for prediction markets

The case centers on a fundamental question: should prediction market platforms be regulated by state authorities or by federal agencies like the CFTC? A Supreme Court decision would set a precedent affecting not just Kalshi but the entire prediction market industry across the United States.

Prediction markets allow users to trade contracts based on the outcomes of real-world events, including sports games. The legal status of these platforms has been debated, with some states treating them as gambling operators and others arguing they are financial instruments overseen federally.

What is confirmed

• The NFL filed an amicus brief supporting New Jersey's Supreme Court petition on October 8, 2026.
• Thirty-nine states and the District of Columbia also filed a brief supporting New Jersey.
• Kalshi has until November 9 to respond to the petition.
• The Supreme Court has not yet decided whether to hear the case.

What is still unclear

• Whether the Supreme Court will grant review of the case.
• How the Court will rule on the question of whether prediction markets fall under state or federal jurisdiction.
• Whether other pending state-level actions against prediction market companies will also reach the Supreme Court.

Sources

• Cointelegraph

Read also: NFL asks Supreme Court to let states regulate prediction markets instead of federal regulators