The National Football League filed a brief with the U.S. Supreme Court on Thursday arguing that prediction markets such as Kalshi and Polymarket should answer to state gambling regulators rather than the Commodity Futures Trading Commission alone. The filing escalates a legal fight that New Jersey has asked the high court to resolve definitively.

The NFL said it raised concerns with the CFTC — which claims exclusive authority over the exchanges — about how the platforms conduct sports wagers, but its requests went unanswered. The league told the court the resulting betting practices "pose real challenges to game integrity and consumer protection."

The NFL was not alone. Former CFTC Chairman Gary Gensler, who later led the Securities and Exchange Commission, and former Senator Chris Dodd, a sponsor of the Dodd-Frank Act, both filed briefs this week backing the states' position. Dodd, who described himself as "uniquely qualified" on the question, wrote that his bill "did not set out to authorize nationwide sports betting through derivatives markets or displace decades of state and tribal primacy over gaming regulation."

Gensler went further, contradicting current CFTC Chairman Mike Selig. "Congress did not transfer jurisdiction over sports betting from the states to the CFTC," Gensler wrote. "When Congress amended the [Commodity Exchange Act] through Dodd-Frank, it was addressing the causes of the recent financial crisis, not undoing federal policy against sports betting and displacing traditional state and tribal regulation."

Why is the league pushing for speed?

The NFL warned that the stakes compound with every season of delay. "Billions of dollars will be bet on NFL games through prediction markets each season, and any delay from the court will result in increasing consumer harm and risk to game integrity," the league said in its brief.

The legal backdrop is split. One federal court has backed Kalshi's argument that the CFTC should be its sole regulator, while two others have sided with states claiming authority under their own gambling laws. The NFL described that division as leaving companies and leagues in uncertain and hazardous legal terrain.

The league's substantive complaints against CFTC oversight target three gaps:

• The platforms permit wagering that can be manipulated by the choices of single players.
• They allow people younger than 21 to bet.
• The federal agency lacks enough staff to police the markets as effectively as state regulators.

The NFL said the federally regulated firms "are not subject to the same rigorous regulatory constructs and oversight provided by state gaming authorities," and it accused the CFTC of "a more laissez-faire approach" than the states apply.

What does Kalshi say?

Kalshi disputes the league's account of their dealings. "We have consistently tried to engage proactively and constructively with the NFL to collaborate on market integrity with no response," spokesperson Elisabeth Diana said in a statement.

Diana noted that Kalshi has secured partnerships with other professional leagues, including Major League Baseball and the National Hockey League. "All but the NFL have been willing to share data and collaborate to protect game integrity," she said.

The CFTC pushed back on Thursday. "Since day 1, the CFTC has engaged with the NFL regarding the agency's rulemaking agenda and policy priorities," the agency said, calling it "unfortunate" that the league declined an arrangement that would have let it better exchange information with the commission to promote market integrity.

The commission continues to insist that the exchanges it regulates, including Kalshi and Polymarket, operate under federal authority that preempts state power. The Supreme Court must now decide whether to take the case — a decision that will shape whether sports-event contracts sit under the CFTC's derivatives framework or under the patchwork of state and tribal gaming regulators.