The NFL filed a brief at the U.S. Supreme Court on Thursday. It backs New Jersey in its fight with Kalshi, the prediction-market company. New Jersey wants the justices to decide whether states can apply their gambling laws to sports contracts that Kalshi and similar platforms sell under federal rules. Appeals courts have split. One court sided with Kalshi, and two sided with the states. The NFL says these contracts are just sports bets, and that the federal regulator can't police them. On the first Sunday of this NFL season, people traded $3.3 billion on prediction markets. NFL games drew $1.8 billion of that. Kalshi has until Nov. 9 to respond. The Court hasn't said whether it will take the case.

These Are Sports Bets, And States Should Police Them

The NFL, 39 states and a former top federal regulator say Congress never handed sports betting to Washington.

One person can rig some of these bets. The NFL's brief says the riskiest contracts are ones where "a player can alter his performance, a coach can change his team's lineup, or an official can make (or not make) certain calls." The league points to markets on missed field goals, player injuries and officiating decisions. It calls the platforms' insider-trading rules "paper tigers." The league says it asked the CFTC and the platforms to ban easily rigged bets and set a minimum age of 21. They refused.

The federal regulator is too small for the job. The NFL says the Commodity Futures Trading Commission, or CFTC, has 543 employees for the whole country. Nevada and Pennsylvania each have about 400 people regulating gambling. The league also notes that Kalshi lets 18-year-olds trade, while most states set the betting age at 21.

Two former Washington insiders agree. Former CFTC Chairman Gary Gensler filed his own brief Thursday. He wrote that "Congress did not transfer jurisdiction over sports betting from the states to the CFTC." Former Senator Chris Dodd, who co-wrote the 2010 financial law Kalshi relies on, said it never set out "to authorize nationwide sports betting through derivatives markets." Thirty-nine states and D.C. filed a brief the day before. A group of 145 tribes filed one Thursday.

But The Federal Regulator Is Already On The Case

Kalshi and the CFTC say Washington is policing these markets, and the NFL is the one refusing to help.

The regulator says the league refused to sign an information-sharing deal. CFTC public affairs director Brooke Nethercott said "it's unfortunate the NFL declined to sign" the agreement. The agency said it has been in touch with the league about its rulemaking "since day 1."

The platforms say the NFL is the holdout. Kalshi spokesperson Elisabeth Diana said the company has tried to work with the NFL on integrity "with no response." "All but the NFL have been willing to share data and collaborate to protect game integrity," she said. Kalshi says the CFTC "is actively policing sports-related markets."

The industry wants one national rulebook. An industry group, the Coalition for Prediction Markets, said: "National financial markets require a national regulator."

Still, A Partnership Gives Leagues Control

Hockey and baseball signed deals with the platforms and say that lets them limit risky bets.

Leagues can pull bad contracts themselves. In October 2025, the NHL became the first major U.S. league to partner with both Kalshi and Polymarket. NHL Commissioner Gary Bettman said the deal "gives us control, because we have the ability to take down any contracts we don't think are appropriate."

Baseball wrote its limits into the deal. In March, MLB named Polymarket its exclusive prediction-market partner. It also signed an information-sharing pact with the CFTC. The Polymarket deal restricts markets on individual pitches, manager decisions and umpire performance. MLB Commissioner Rob Manfred called the agreements "imperative steps in proactively managing the new and rapidly growing prediction market space." Polymarket said Thursday that it "shares the NFL's commitment to preserving the integrity of the game" and wants "a harmonized federal framework."

Where This Lands

The NFL, the states and Gensler say these contracts are sports bets that belong to the states. The NFL adds that the states, not the CFTC, have the staff to police them. Kalshi and the CFTC say a federal regulator is already watching. They also say the NFL won't cooperate. Hockey and baseball took a third route. They partnered with the platforms and set limits from inside. A league source says the NFL would accept federal rules that match what states require. Gaming attorney Daniel Wallach says the NFL's brief "meaningfully increases the chances" the Court takes the case. Kalshi's response is due Nov. 9.

Sources