SCOTUS Review of Prediction Markets Hits 64% on Polymarket — New Jersey Files Cert Petition September 3
Polymarket's contract on Supreme Court review of prediction markets by year-end jumped from 30% to 64% within hours of the Ninth Circuit's August 28 ruling, generating $976K in volume. New Jersey files its certiorari petition September 3. The Third Circuit vs Ninth Circuit split on the same statutory question is the clearest available trigger for SCOTUS to take the case.
The probability of Supreme Court review of prediction market sports contracts by year-end 2026 jumped from roughly 30% to 64% on Polymarket's own platform within hours of the Ninth Circuit's 3-0 ruling on August 28, with over $976,000 in trading volume flowing into the contract over the weekend. New Jersey, the losing party in the Third Circuit's April ruling that went for Kalshi, files its certiorari petition on September 3 — asking SCOTUS to review the decision that blocked NJ from enforcing gambling laws against Kalshi. The Ninth Circuit's ruling, issued five days before NJ's filing deadline, transforms the petition from a challenge to a lone circuit ruling into an application presenting a direct, explicit circuit split on a federal statutory question.
For UK readers, the SCOTUS mechanics are the important element. The US Supreme Court grants review in roughly 1-2% of petitions overall. Petitions that present a clear circuit split — two federal appellate courts ruling opposite ways on the same federal statutory question — have materially higher grant rates, and SCOTUS has a longstanding practice of taking cases where circuits conflict on the interpretation of a federal statute. The CEA's definition of a 'swap' is a federal statutory question; the Third Circuit (April) and Ninth Circuit (August 28) have now answered it in opposite directions for the same type of contract. UK lawyers familiar with the UK Supreme Court's approach to statutory conflicts will recognise the same logic: when two senior courts disagree on the meaning of a statute, the apex court must eventually resolve the question to prevent the law varying by geography. The only question in the US context is timing — whether SCOTUS grants the NJ petition immediately or waits for additional circuit development.
The commercial stakes during the cert-consideration window are unprecedented for a financial regulatory SCOTUS case. The NFL regular season begins September 4 and will generate an estimated $4 billion-plus in prediction market sports volume in September alone. The Court typically takes several months to act on a certiorari petition; if it grants NJ's September 3 filing, oral argument would likely be scheduled for late 2026 or early 2027 with a ruling by June 2027. During that window, the US prediction market sector will operate under a patchwork: CFTC emergency orders protecting platforms in states that have sued, Ninth Circuit precedent empowering nine western states to enforce, and the commercial reality of NFL-season volume running at billions per month regardless of the legal outcome.
The CDC Gaming analysis published after the Ninth Circuit ruling noted that despite NJ's petition and the circuit split, SCOTUS may decline to take the case immediately, preferring to let additional circuits weigh in before granting review. The Second Circuit has two simultaneous Kalshi appeals (New York and Connecticut) that could be consolidated and decided within months; the Sixth Circuit has the Michigan case. If either the Second or Sixth Circuit also rules against Kalshi, the case for urgent SCOTUS intervention strengthens further. The 64% Polymarket contract price implies the market is pricing a majority-likely outcome that SCOTUS intervenes before year-end — a probability that would have seemed far-fetched before the Ninth Circuit's unanimous ruling.
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Recent updates
Massachusetts Supreme Court Ruling on Kalshi Now Imminent — First State High Court Decision on Prediction Markets
The Massachusetts Supreme Judicial Court is expected to rule within weeks on whether Kalshi's sports event contracts constitute illegal sports gambling under state law — the first time any US state supreme court has decided this question. The SJC appeared skeptical of Kalshi's CFTC-preemption argument at May 5 oral arguments. A coalition of 38 state attorneys general backed Massachusetts; the CFTC backed Kalshi. The outcome will be the first state apex court ruling on prediction markets anywhere in the country.
27 States Back California Tribes Suing Kalshi Over Sports Contracts Under Indian Gaming Law
Three California tribes are pursuing a separate Ninth Circuit case against Kalshi's sports contracts under the Indian Gaming Regulatory Act — a 1988 federal law governing tribal gaming rights that is independent of the CEA preemption arguments in the Nevada, NJ, and Connecticut cases. The Ninth Circuit refused consolidation with the Nevada case. A panel appeared skeptical of Kalshi in July. 27 states plus DC filed amicus supporting the tribes.
Ninth Circuit Rules 3-0: Kalshi's Sports Contracts Are Not Swaps — States Can Regulate Them as Gambling
A unanimous Ninth Circuit panel has ruled Kalshi's sports event contracts are not 'swaps' under federal law and that states can regulate them as gambling — directly contradicting the Third Circuit's April ruling in Kalshi's favour. The decision covers nine western states including California. New Jersey is preparing a Supreme Court petition. The NFL regular season opens September 4.