In a recent ruling, a federal judge has temporarily blocked Arizona's attempt to bring criminal charges against Kalshi, a prediction market provider. The decision was made in response to a motion filed by the Commodity Futures Trading Commission. District Judge Michael Liburdi of the District of Arizona ruled that Arizona cannot proceed with an arraignment of Kalshi, which was scheduled for Monday, April 13.

Last month, Arizona announced plans to file 20 criminal charges against Kalshi, claiming that the company's offerings violated state law. However, Judge Liburdi found that the CFTC is likely to succeed in its claim that Arizona's gambling laws are preempted by the Commodity Exchange Act. The judge granted a temporary restraining order for two weeks, citing the possibility that Arizona's actions might violate the Supremacy Clause. A pending motion for a preliminary injunction may extend the temporary order.

The CFTC has argued that prediction markets, also known as event contracts, are subject to federal supervision and that state law is preempted. The regulator's chairman, Michael Selig, welcomed the judge's decision, stating that Arizona's use of state criminal law against companies complying with federal law sets a dangerous precedent.

The case is part of a broader debate about the regulation of prediction markets, with mixed results in state and federal courts. While some state courts have sided with states, federal courts have had varying outcomes. The Ninth Circuit Court of Appeals will hold a hearing on a consolidated case next week, allowing providers and other parties to argue their positions.