SCOTUS Review of Prediction Markets Hits 64% on Polymarket — New Jersey Files Cert Petition September 3
The probability of Supreme Court review of prediction market sports contracts jumped from around 30% to 64% on Polymarket's own platform within hours of the Ninth Circuit's August 28 ruling — with $976,000 in trading volume flowing into the contract. New Jersey, the losing party in the Third Circuit's April ruling that went for Kalshi, is filing a certiorari petition on September 3. The Ninth Circuit's 3-0 ruling against Kalshi directly contradicts the Third Circuit's 2-1 ruling for Kalshi, creating the clearest possible circuit split trigger for SCOTUS to grant review.
The probability that the Supreme Court will take a prediction market case by the end of 2026 jumped from roughly 30% to 64% on Polymarket within hours of the Ninth Circuit's August 28 ruling, with more than $976,000 in trading volume flowing into the contract over the weekend. The movement reflects a specific legal mechanics argument: a circuit split between two federal appellate courts on the interpretation of the same federal statute — the Commodity Exchange Act's definition of a 'swap' — is the strongest available trigger for SCOTUS to grant review. The Third Circuit ruled 2-1 in April that Kalshi's sports event contracts ARE swaps subject to CFTC exclusive jurisdiction; the Ninth Circuit ruled 3-0 on August 28 that they likely are NOT swaps and that states can regulate them as gambling. The same statutory question has two opposite answers in two circuits. SCOTUS exists to resolve exactly this kind of conflict.
New Jersey is the losing party from the Third Circuit's April ruling — the court sided with Kalshi and against the state's attempt to enforce gambling laws. NJ is filing a certiorari petition on September 3, asking SCOTUS to review that April decision. The Ninth Circuit's ruling, issued five days before the NJ filing deadline, changes the petitioner's posture significantly: instead of asking SCOTUS to review a lone district-and-circuit ruling in a nascent legal area, New Jersey can now point to an explicit circuit split on the same statutory question. SCOTUS grants review in roughly 1-2% of cert petitions overall; petitions presenting a clear circuit split on a federal statutory interpretation question are far more likely to be granted. The prediction market question — which Congress arguably did not anticipate when it wrote the CEA's swap definition — adds a 'case of national significance' weight that further increases cert probability.
The practical stakes if SCOTUS takes the case are enormous. A ruling that sports event contracts ARE swaps within CFTC exclusive jurisdiction would invalidate all state enforcement actions against CFTC-licensed prediction market operators, effectively giving Kalshi, Polymarket US, Robinhood Rothera, and DraftKings Predictions a national operating license. A ruling that they are NOT swaps would validate state-by-state enforcement and potentially require CFTC-licensed platforms to obtain state gambling licenses in every jurisdiction where they operate sports contracts — a fundamentally different business model. The NFL regular season, beginning September 4, will generate billions in prediction market sports volume during the period in which the Court is deciding whether to accept the case. September NFL volume alone may exceed $4 billion across platforms. The commercial stakes during the cert-consideration window dwarf anything the Court would typically encounter in a financial services regulatory case.
SCOTUS timing, if it grants certiorari on the NJ petition, points toward a decision in the Court's October 2026 term — with oral argument in late 2026 or early 2027 and a ruling by June 2027. During that window, the prediction market sector will operate under legal uncertainty: CFTC emergency orders protecting platforms in New York and Michigan, Ninth Circuit precedent supporting state enforcement in nine western states, a pending Second Circuit consolidation of two Kalshi appeals, and a Sixth Circuit Michigan case. CDC Gaming analysts noted that despite NJ's petition, SCOTUS may not hear the case immediately — the Court sometimes waits for additional circuit development before granting review. But the Ninth Circuit's 3-0 ruling, following five consecutive PI denials against Kalshi, suggests the appellate development needed to justify SCOTUS involvement has arrived.
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Recent updates
Kalshi Suspends Congressional Candidate for Trading on Own Race — Senate Already Banned Members
Kalshi disclosed on August 31 that it suspended North Carolina congressional candidate Laurie Buckhout for three years and fined her $2,589 for trading on her own race — the first publicly known enforcement action against a candidate for prediction market insider trading. Kalshi said it found multiple politicians trading on races they were involved in, including former Congressman George Santos. The Senate had unanimously banned its members and staffers from prediction market trading on April 30. CNN published a major feature on September 24 documenting election officials' concerns about disinformation and insider trading risk from prediction markets as the midterms approach.
Pew Research: Prediction Market Volume Doubled May-July, Sports Now Largest Category
A Pew Research Center analysis published September 23 found that combined monthly trading volume on Kalshi and Polymarket more than doubled from May to July 2026 — rising from $26 billion in May to $53 billion in July — driven primarily by sports contracts. Sports is now the largest trading category on both platforms. During the FIFA World Cup in June and July, Kalshi's monthly sports volume reached $58 billion. Over the same period, Americans wagered roughly $40 billion at licensed sportsbooks — suggesting prediction market sports volume has approached or exceeded licensed sports betting in dollar terms.
Democrats Now 60% Senate, 90% House Favorites on Prediction Markets — Biggest Shift Since 2024
Prediction markets on Kalshi and Polymarket have moved decisively toward Democratic control of both congressional chambers in the 2026 midterms. Democrats are priced at approximately 60% to win Senate control (Republicans 40%) and roughly 90% to win House control as of September 21. Republicans had been at 80%+ in Senate control markets when the market opened in November 2024. The shift began in February 2026 following the Iran war and has accelerated through fall as rising gas prices pushed Trump's approval ratings lower. More than 500 active midterm markets are live across Kalshi and Polymarket combined.