Robinhood's Missouri complaint tests CEA preemption on new ground

Robinhood filed its complaint in the Eastern District of Missouri naming Attorney General Catherine Hanaway as defendant, seeking a temporary restraining order, a preliminary injunction, and a permanent injunction. The trigger was a Missouri Gaming Commission cease-and-desist letter dated September 16, which told Robinhood to stop offering sports event contracts on the grounds that the company holds no Missouri gaming licence.

The cease-and-desist is straightforward state enforcement. What Robinhood filed in response is more interesting than it looks.

The argument runs through the Commodity Exchange Act's exclusivity clause: Congress gave the CFTC jurisdiction over designated contract markets and the products listed on them, and that grant of exclusive federal jurisdiction displaces state gaming law under the Supremacy Clause. Robinhood's complaint states this plainly — Missouri's position, it argues, cannot be reconciled with the CEA. Courts have seen versions of this argument before. Kalshi used it to secure a temporary restraining order in New Jersey, and that precedent is part of what is giving Robinhood's lawyers somewhere to stand.

There is a second argument, less discussed, that matters more. Robinhood contends that complying with Missouri's licensing requirement would itself create a federal problem: a CFTC-regulated derivatives platform cannot take on state gaming licensure without compromising the federal designation that permits it to operate at all. The compliance trap runs both directions. This is the structural argument that the courts have not fully resolved, and it is the reason the Missouri litigation carries weight beyond Missouri.

Polymarket filed separately, in the same state, but on a different legal theory — Commerce Clause, not CEA preemption. That divergence is not cosmetic. Commerce Clause challenges ask a federal court to find that Missouri's enforcement discriminates against or excessively burdens interstate commerce. CEA preemption asks the court to find that the field is already occupied by federal law, full stop. The first argument requires a balancing test. The second, if it holds, requires nothing except a reading of the statute. Robinhood and Kalshi have chosen the stronger position in terms of potential reach, but also the one where a loss would close more doors.

The courts that have heard preemption arguments from these platforms have so far given preliminary relief, not final rulings. A temporary restraining order tells you the judge sees a serious question; it does not tell you how the question resolves. The Ninth Circuit upheld Nevada's ban on Kalshi contracts, which means preemption has already failed at the appellate level in one circuit. The Eastern District of Missouri is in the Eighth. What that court does with Robinhood's complaint will not bind New Jersey or Nevada, but it will add to a circuit map that is currently producing contradictory answers.

The compliance trap argument is the one worth watching in Robinhood's filing. If a court accepts it — that federal designation and state licensing are structurally incompatible, not merely in conflict on this specific product — the enforceability of state cease-and-desist letters against federally registered platforms collapses regardless of which theory the platform argues. No court has accepted that version of the argument yet.