New Jersey Takes Prediction Market Fight to the Supreme Court
New Jersey is heading to the Supreme Court in its battle with Kalshi. The state that forced the legalization of sports betting nationwide now wants the highest court to decide whether federal law preempts state gambling rules on sports prediction markets.
A joint status report filed by Kalshi and New Jersey attorneys asked the lower court to stay proceedings while the Supreme Court reviews the Third Circuit’s 2-1 decision. That ruling found Kalshi was likely to succeed because federal laws preempt state gambling regulations. The dissenting judge wrote that because Kalshi is facilitating gambling it can be subjected to state regulation.
The move sets up a potential landmark decision. After eighteen years on bookmaker trading floors I have seen how operators price risk when the rules are clear. Prediction markets sit in a gray zone that books never tolerated.
The Third Circuit Split and Its Limits
The Third Circuit ruled 2-1 that Kalshi’s sports markets are likely legal under federal preemption. The majority view treats event contracts as distinct from state gambling laws. The dissent took the opposite position.
This is not the first 2-1 split we have seen in these cases. The same court split on the original sports betting challenge before the Supreme Court stepped in. Operators watched those fights closely because the liability side of the P&L changes the moment the rules flip.
The data is already moving. Polymarket currently prices an 18% chance the Supreme Court accepts a sports event contract case by the end of the year. That number reflects trader skepticism more than legal analysis.
Expert Views Split on Likely Outcome
Legal experts differ sharply on the Supreme Court’s direction. Daniel Wallach, one of the leading voices in prediction market litigation, gives it a 70-80% chance the court rules against prediction markets.
Kayvan Sadeghi, a partner at Jenner & Block in New York, points to the court’s conservative makeup and its sympathy for states’ rights arguments. Even with Trump administration support for prediction markets, the bench leans toward letting states regulate gambling.
Law professor Melinda Roth sees it closer to a 50-50 proposition. She notes the 2018 sports betting decision does not necessarily dictate the outcome here. That ruling struck down a federal prohibition and affirmed states’ rights to decide. The current fight is whether federal law already clears the field for event contracts.
Bookmakers never operated in this ambiguity. Trading desks required clear regulatory lines before laying significant liability. Prediction platforms have scaled without that clarity. The Supreme Court decision will reset the risk models on both sides.
Timeline Realities and the Nevada Factor
Kalshi filed its lawsuit against New Jersey authorities in April last year after receiving a cease-and-desist letter. These cases move slowly. The sports betting path took years of persistence, rejections in 2014, a petition in 2016, acceptance in 2017 and the final ruling in 2018.
Melinda Roth believes it will be at least another year before the Supreme Court hears the case. A pending Ninth Circuit ruling on Nevada’s challenge could accelerate the timeline. If that court favors the state it would create a circuit split and increase the odds the Supreme Court steps in sooner.
From the trading floor perspective the uncertainty itself carries cost. Sportsbooks hedge when lines move on new information. Prediction market operators and their users currently price in regulatory risk without a clear hedge. That gap explains why sharp money watches these cases so closely.
Risk of Overreading the 2018 Precedent
The 2018 Supreme Court sports betting decision is the obvious reference point. It dismantled a federal ban and returned authority to the states. Some read that as automatic support for state-level gambling regulation here.
Others argue the federal statutes governing commodity markets create different preemption questions. The Third Circuit majority leaned on that distinction. The dissent did not.
A Supreme Court loss for prediction markets would not kill the category outright. It would push operators toward state-by-state licensing or toward non-sports contracts. Either path changes the liquidity profile and the margin structure that trading desks care about.
The counterargument is that clarity itself has value. Eighteen years of watching bookmakers adapt to new state regimes shows operators eventually price in regulatory overhead. The faster the Supreme Court draws the line the sooner the real market-making begins.
The Bottom Line
New Jersey’s petition sets the stage for the Supreme Court to decide whether sports prediction markets operate under federal preemption or state gambling rules. The Third Circuit’s split, expert odds ranging from 50-50 to 70-80% against, and Polymarket’s 18% probability on near-term acceptance all point to a high-stakes outcome that will reshape risk models across books and platforms alike. The sports betting precedent offers clues but no guarantee. Once the court rules, operators on both sides will adjust their pricing, their liability books, and their product roadmaps within weeks. The data will tell us who got it right.
