Supreme Court silence on prediction markets lets state battles multiply

Scott Kaufman-Ross distributed the NBA memo on a Friday. By Monday, Underdog had filed in Nashville. These are not unrelated facts.

The NBA's new restrictions on player statistical unders — parlays involving multiple under bets on the same player, wagers on opening-tip outcomes, prop bets on players expected under twelve minutes — are a direct response to the Terry Rozier and Jontay Porter cases. Kaufman-Ross said as much. The league is sealing the door through which those specific schemes entered. That is defensible, and probably correct.

What the memo cannot do is address the deeper structural problem, which is that the line between a sportsbook and a prediction market has become the most contested boundary in American financial regulation, and nobody with authority to draw it permanently has chosen to do so.

The Sixth Circuit ruled in late September that Ohio and Tennessee gaming regulators may apply state law against prediction market platforms. Underdog filed its Nashville complaint this month, arguing that federal preemption should govern and that Tennessee's enforcement posture leaves it a choice between two forms of irreparable harm. Crypto.com and Novig have sued Missouri on the same federal preemption theory. Kalshi, Polymarket, and Robinhood held off from joining that Missouri action — a strategic divergence worth noting, because it suggests these companies do not share a unified read on where the favorable ground is.

The CFTC has moved forward with an interim rule and a proposed classification for sports event contracts. State attorneys general are treating that guidance as advisory at best. The Supreme Court has declined to intervene. That combination produces exactly what you see: every state becomes its own jurisdiction, every ruling buys a temporary reprieve for whichever party won that week, and the underlying question — whether these contracts are CFTC-regulated derivatives or state-regulated gambling products — remains structurally open.

The reporting frames this as a regulatory maelstrom. From inside a previous position working on exactly this kind of jurisdictional ambiguity, what it looks like is something more specific: it looks like a situation that state regulators have correctly identified as favorable terrain. When federal guidance exists but carries no enforcement weight, and when the Supreme Court stays silent, state-by-state litigation is not chaos — it is the regulated outcome of a power vacuum. The states filing against prediction markets are not confused about the law. They are exploiting the gap between what the CFTC has proposed and what it can compel.

Underdog and its peers are not wrong about the federal preemption argument. They may well be right. But being right in Nashville does not resolve the question in Missouri, or Ohio, or any of the other states where this fight continues. The Sixth Circuit ruling suggests that at least one federal appellate court is comfortable letting state regulators proceed, which means the preemption argument is not the clean win the prediction market platforms need it to be.

The NBA restrictions and the state enforcement actions are different problems with the same root: the category of these contracts has not been settled. Until a court with national authority or a Congress with the appetite to act decides what a sports event contract actually is, both the league and the states will keep drawing their own lines.