The NFL has lined up on the opposite side of the Trump administration in the biggest American sports-betting case now in the courts. In an amicus brief filed on Thursday, the league urged the Supreme Court to take up New Jersey’s appeal in Flaherty v. KalshiEX and to rule that contracts on NFL games are gambling, not financial swaps.
Former US Attorney General William Barr represents the league. His client is pushing a position the sitting president publicly opposed in May, when Donald Trump said he backed the Commodity Futures Trading Commission “as the sole regulator” of the sector.
Prediction markets let users buy and sell contracts on the outcome of real-world events, from a touchdown to a playoff berth to a Week 18 result. Platforms including Kalshi say those contracts are regulated derivatives, overseen in Washington by the CFTC, and therefore exempt from state gambling laws.
$1.8 billion traded in one Sunday
The scale is already significant. NFL-related contracts accounted for $1.8 billion of the $3.3 billion traded on prediction markets on the opening Sunday of the current season, according to the league’s filing.
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“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 wrote in the brief.
The NFL argues the CFTC does not have the people to police that market. The agency has just 543 employees nationwide. Nevada and Pennsylvania each have close to 400 gambling regulators alone. The brief dismisses the platforms’ insider-trading safeguards as “paper tigers”.
Specific contracts also come under attack. The league says wagers that can be moved by a single individual, including on missed field goals, officiating decisions, injuries and individual plays, should be dropped. It says it asked both the CFTC and the operators to pull those products, and was refused. The league also notes the age gap, with 18-year-olds able to trade on Kalshi while most states require sports bettors to be 21.
Trump’s CFTC on the other side
Since Trump returned to office, his CFTC has sued at least nine states, including Arizona, Minnesota, Wisconsin, Illinois, New York and Connecticut, arguing their enforcement actions against Kalshi and Polymarket are preempted by federal law. Donald Trump Jr. has publicly backed the platforms.
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The appeals courts are split. The Third Circuit ruled for Kalshi in the decision New Jersey is now appealing. On 28 August 2026 the Ninth Circuit went the other way, ruling 3-0 in KalshiEX, LLC v. Assad that sports event contracts are not swaps under the Commodity Exchange Act and that federal law does not preempt state gambling regulation.
New Jersey is not alone. The attorneys general of 39 states and the District of Columbia have filed in support, and former CFTC and SEC chair Gary Gensler and former Senator Christopher Dodd, co-author of the Dodd-Frank Act, have joined on the same side.
Kalshi response due 9 November
Kalshi did not immediately respond to Bloomberg’s request for comment on the NFL brief. The company’s own response to the Supreme Court is due by 9 November, with the justices expected to decide by December whether to hear the case.
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