The NFL's amicus brief against Kalshi is the clearest sign yet that America's biggest sports league does not want prediction markets operating outside the state-regulated betting system. In a 32-page filing, the league backed New Jersey's request for the Supreme Court to hear its fight with Kalshi, arguing that delay will bring "increasing consumer harm and risk to game integrity." The case could decide whether sports event contracts sit under federal oversight alone or whether states can regulate them, and the answer will shape the future of sports betting in the United States. Here is what the NFL said, how the courts have split, and why poker and sportsbook players should pay attention.
What the NFL filed
According to Card Player and The Lines, the NFL filed an amicus curiae, or "friend of the court," brief supporting New Jersey regulators in their petition to the Supreme Court. The underlying question is whether sports event contracts fall exclusively under federal oversight through the CFTC, or whether states can regulate them as gambling.
The league's core arguments, as reported:
- More than half of prediction-market volume on the first Sunday of the 2026 season was tied to NFL games. The Lines puts a figure on it: football contracts made up $1.8 billion of the $3.3 billion traded across prediction markets that day, per the NFL's filing.
- Prediction markets lack the regulatory framework and consumer protections that state-regulated sportsbooks have.
- Delay carries risk. In the league's words, "any delay from the Court will result in increasing consumer harm and risk to game integrity."
- Certain contracts are objectionable: bets on players returning from injury, what announcers will say, and other "easily manipulable" markets. The Lines adds that the league flagged contracts on officiating decisions and events participants could influence, and wants a minimum trading age of 21, compared with Kalshi's current 18.
The courts are split
The legal backdrop explains why the Supreme Court looks likely to step in. Card Player reports that the Third Circuit ruled for Kalshi, finding that New Jersey had no jurisdiction to bar it from offering sports event contracts. The Sixth and Ninth Circuits ruled the other way, favoring state authority; the NFL says they "got it right" under "the current landscape."
When federal appeals courts disagree, the Supreme Court is the only body that can settle the matter. The Lines reports that 39 state attorneys general and a Native American tribe also backed New Jersey's request for review. Most legal experts expect the issue to reach the justices, and industry legal expert Daniel Wallach said a ruling could come as early as June 2027.
Why the NFL is breaking ranks
What makes the filing notable is that leagues are not united. Card Player reports that MLB and the NHL have entered deals with prediction markets enthusiastically, and the NBA has reportedly been negotiating one. The NFL has been more restrained. It has close relationships with sportsbooks and has shaped their offerings, so it has a lot to lose if bettors migrate to a less regulated channel.
There is a commercial logic to that stance. Licensed sportsbooks pay state taxes, follow integrity-monitoring rules and share data with leagues. Prediction markets operating under federal oversight might not offer the same revenue streams or safeguards. Whether the league's concern is principle, protection of its partners or both, it is putting its legal weight behind the states.
We have followed this fight from several angles. Our prediction markets vs. sports betting analysis explains the regulatory contest, while our report on Kalshi's state lawsuits tracks the legal escalation. The scale of the football betting market is covered in our piece on the NFL betting handle record.
The lobbying angle
Money is also flowing in the other direction. The Lines reports that Kalshi, Polymarket and the Coalition for Prediction Markets spent at least $3 million on lobbying and political contributions in 2026, and that Kalshi has hired lobbyists in 41 states.
One name has drawn attention. Card Player reports that former Arkansas Democratic senator Blanche Lincoln, who chaired the Senate Agriculture Committee in 2010 and helped write Dodd-Frank provisions that let the CFTC bar certain event contracts including those on sporting events, now lobbies for Kalshi. At the time she said such contracts "would not serve any real commercial purpose" and "would be used solely for gambling." The New York Post reported Kalshi has paid her $480,000 since 2024. Her firm, Lincoln Policy Group, says her current work reflects a view that "properly regulated prediction markets can serve legitimate financial purposes" and that consumer safeguards are in place.
It is not a scandal that a former lawmaker changes her view or takes lobbying work, and she is entitled to argue for federal control. But the shift illustrates how high the stakes are, and why a ruling matters.
The CFTC wildcard
Another development complicates the picture. The CFTC issued an interim final rule to clarify what counts as a "swap." Chairman Michael S. Selig said "Casino-style gambling products are not derivatives." Card Player notes the rule appears to exclude sports event contracts, even though it lists "sports wagers" under casino-style products. The rule has a 30-day written comment period, so industry and state responses should arrive soon.
If the CFTC's own definitions lean against sports contracts, that could strengthen the states' hand. If not, the Supreme Court may have to resolve the ambiguity itself.
What this means for bettors and players
For ordinary bettors, the fight is easy to overlook, but the consequences are practical.
- Where you can bet. A federal win for prediction markets would mean sports contracts available nationwide, including in states that have not legalized sports betting. A state win would keep legal sports wagering within licensed sportsbooks and leave prediction markets to fight for narrower territory.
- Consumer protection. Regulated sportsbooks have mandatory responsible-gambling tools and dispute processes. Whether prediction markets match them is a central issue in the case.
- Integrity. Contracts on injuries or announcer words raise obvious manipulation risk. The league's objection to them is one many fans will understand.
- Age limits. The NFL wants 21 as a minimum; Kalshi currently allows 18.
If you bet on sports, stick to licensed operators where you have clear recourse. Our sportsbooks guide compares options, and offshore-friendly choices include BetOnline Sportsbook and Sportsbetting.ag. Always check the rules in your state or country, and set limits you can afford.
The poker connection
Why does this matter for a poker site? Because the boundaries of "gaming" are being redrawn in real time. States that have resisted online poker point to the same arguments about consumer protection and integrity. Federal-state battles over who regulates games of skill and chance shape whether more states will legalize poker, which we track in our US online poker outlook. A Supreme Court decision on federal preemption could influence those debates well beyond sports.
Poker players also share a stake in the integrity conversation. The same concerns that lead the NFL to attack "easily manipulable" markets underpin the security measures operators are adopting after recent scandals, such as those we covered in our GGPoker software ban report.
What to watch
Watch for the Supreme Court's decision on whether to take the case, the CFTC rule's comment period and any further league deals with prediction markets. A ruling in 2027 would settle a question that has divided circuits, tribes and regulators. Until then, the NFL has made its position unmistakable: it wants betting on its games to stay where regulators, sportsbooks and the league can see it.