The NFL has backed a Supreme Court challenge that could change how sports prediction markets operate across the United States, siding with New Jersey regulators in their legal battle against Kalshi.
The league filed a brief on 8 October 2026, arguing that sports event contracts are gambling products rather than financial derivatives. With billions of dollars now being traded on NFL-related markets, the disagreement has become difficult for regulators to ignore.
NFL Betting Contracts Hit $1.8 Billion on Opening Sunday
The NFL says $1.8 billion of the $3.3 billion traded across prediction markets on the opening Sunday of the 2026 season involved its games. That means NFL contracts accounted for more than half of the day’s reported trading volume.
The figures were presented in the league’s submission to the Supreme Court, according to Associated Press.
That volume helps explain why the NFL is pushing for a ruling now. Prediction markets are no longer a small alternative to conventional sportsbooks. They have become a substantial part of the wider sports wagering business.
Unlike traditional bookmakers, platforms such as Kalshi allow customers to trade event contracts, typically linked to a yes-or-no outcome. The operators argue these are financial products regulated federally by the Commodity Futures Trading Commission (CFTC).
The NFL disagrees. It argues that wagering on sporting outcomes should fall under state gambling laws, regardless of whether the transaction is described as a trade or a bet.
Why the NFL Is Backing New Jersey Against Kalshi
The league has joined New Jersey’s request for the Supreme Court to review an earlier ruling that favoured Kalshi.
In April 2026, the Third Circuit Court of Appeals concluded that Kalshi was likely to succeed in its argument that federal commodities law overrides New Jersey’s attempts to regulate its sports contracts.
Other federal appeals courts have taken a different view. That disagreement has left operators and regulators facing different legal interpretations depending on the jurisdiction. The dispute follows a wider multi-state crackdown on prediction markets, as regulators challenge the legal status of sports event contracts.
The NFL’s 8 October filing supports New Jersey’s position. A coalition of 39 states and the District of Columbia has also backed Supreme Court review.
The central question is whether federal approval of event contracts prevents individual states from applying their gambling laws.
The case is Flaherty v. KalshiEX, LLC, No. 26-299. The official Supreme Court docket records the NFL’s submission and the other supporting briefs.
The NFL Wants Stricter Rules on Sports Contracts
The NFL’s objections go beyond the legal definition of a prediction-market contract.
The league has raised concerns about insider information, game integrity and the safeguards available to people trading on sporting events.
Two demands stand out:
- Minimum age of 21: The league has pushed for an age restriction comparable to those used in many state-regulated sports betting markets.
- Restrictions on sensitive markets: The NFL wants tighter controls on contracts involving events that someone inside a team or competition could know or influence before the wider public.
The second point matters particularly for player props and narrow in-game markets.
A contract on the winner of the Super Bowl is one thing. A market involving a specific play or an event potentially known in advance raises a different set of integrity concerns.
The NFL also questions whether the CFTC has sufficient staff and resources to supervise sports wagering on this scale.
Those are the league’s arguments, not findings that prediction-market operators have violated the law.
Kalshi and Polymarket Defend Federal Regulation
Kalshi rejects the suggestion that sports prediction markets lack proper oversight.
The company maintains that the CFTC already supervises federally registered exchanges and has enforcement powers covering market manipulation and other misconduct.
Kalshi has also pointed to its partnerships with Major League Baseball and the NHL as evidence of its commitment to protecting sports integrity.
Polymarket has similarly defended a consistent federal regulatory framework, arguing that a patchwork of different state rules could create problems of its own.
The distinction matters. Prediction markets are not operating entirely outside regulation. The dispute concerns which regulatory system should govern their sports-related contracts and whether federal supervision is sufficient.
What Could Change for US Bettors?
A Supreme Court ruling favouring state regulators could force prediction-market operators to rethink where and how they offer sports contracts.
State-by-state access: Products available under a federal exchange framework could face additional restrictions in states where sports gambling is prohibited or subject to different licensing rules.
Market availability: Certain player props and in-game contracts could face tighter controls if state gambling standards apply.
Age requirements: A move towards a minimum age of 21 would affect younger customers who can currently access eligible event-contract platforms.
Competition with sportsbooks: Prediction markets have provided another route into sports wagering, including in jurisdictions where conventional sportsbooks face restrictions. A change in regulatory authority could narrow that difference.
None of these outcomes is automatic. The consequences would depend on the Court’s eventual ruling and how regulators respond.
For now, anyone comparing sportsbook odds with prediction-market contracts should also account for transaction fees, settlement rules and whether the product is available in their jurisdiction. A better-looking price does not necessarily produce a better net return.
What Happens Next in the Kalshi Court Case?
The Supreme Court has not yet agreed to hear New Jersey’s appeal.
Kalshi has until 9 November 2026 to respond to the petition. The justices will then consider whether to take up the dispute, with a decision on whether to hear the case potentially arriving before the end of the year.
For Betfinder, the wider issue is straightforward: the same sporting outcome can be offered as a traditional sportsbook bet or an exchange-traded event contract, yet face different regulatory requirements.
The NFL wants that distinction tested in the country’s highest court. With $1.8 billion in NFL-related prediction-market trading reported on a single Sunday, there’s plenty at stake for operators, regulators and customers.
