The American Gaming Association (AGA) and a coalition of 145 Tribal parties have urged the US Supreme Court to review New Jersey's dispute with Kalshi over sports event contracts.
Their separate briefs were submitted on October 8 in support of state gaming regulators' petition.
The petition challenges an April ruling by the Third Circuit Court of Appeals. That court upheld preliminary relief preventing New Jersey from applying its sports wagering laws to Kalshi's contracts while litigation proceeds.
The Supreme Court has yet to decide whether to hear the case or rule on the underlying legal question.
Kalshi operates a federally registered derivatives exchange and maintains that the Commodity Exchange Act gives the Commodity Futures Trading Commission (CFTC) exclusive authority over its event contracts.
The CFTC has also asserted federal jurisdiction over registered prediction markets. New Jersey argues that the contracts are sports wagers subject to state gaming law.
The AGA represents US casino operators, suppliers and sportsbooks. Its brief says licensed operators invest in state-specific systems for geolocation, account controls, permitted wagers and reporting, while paying licensing fees and taxes.
It contends that a competing sports product offered through prediction markets can avoid those requirements under the Third Circuit's approach.
The association points to safeguards for younger consumers, statewide self-exclusion, advertising and college sports betting. It argues that Kalshi accepts sports trades from users aged 18 to 20 in states that set 21 as the minimum age for sportsbook wagers. Those claims are arguments made by the AGA rather than findings by the Supreme Court.
The Tribal brief was submitted on behalf of 130 federally recognized Tribes and 15 Tribal organizations. It says the Indian Gaming Regulatory Act gives Tribes authority over gaming on their lands, often through compacts negotiated with states.
The coalition argues that contracts available on those lands without Tribal authorization could undermine exclusivity and revenue used for public services.
Tribal gaming facilities generated more than $46bn in gross gaming revenue in FY2025, according to data cited in the brief. That figure covers Tribal gaming as a whole, rather than the value of the contracts in this case. The filing also identifies litigation brought by Tribes over event contracts in other jurisdictions.
The Third Circuit's preliminary ruling contrasts with later Sixth and Ninth Circuit decisions that rejected Kalshi's position in related cases. Kalshi's response to New Jersey's petition is due November 9.
On October 7, Ohio, 38 other states and DC filed a separate supporting brief in the same Supreme Court petition. Their filing also challenges the view that federal commodities law prevents states from applying sports betting rules to event contracts.
The Tribal brief says Tribal governments spend more than $450m annually on gaming regulation
