Arizona charged Kalshi, and then a federal court stopped Arizona

Arizona is the state that went furthest and lost, at least for now. Its Department of Gaming sent Kalshi a cease-and-desist directing it to cease gambling operations in Arizona and threatening criminal charges. Five days later the attorney general filed a twenty-count criminal information, reported as the first criminal prosecution ever brought against a prediction market platform.

A federal court then blocked Arizona from enforcing. Attorney General Kristin K. Mayes also signed the 37-state brief, so Arizona is arguing the same position in two places at once and has lost the first round in one of them.

Three questions get answered as though they were one

Most state lists you will find are answering a different question from the one in their headline. The three that get run together:

1. Is it lawful for me to trade here? State law.
2. Will the platform let me in? Geofencing, which the platform sets and can change without notice.
3. Am I eligible for the sign-up promo? A marketing offer.

The state legality hub sets out which attorneys general have taken a position on the record, across all fifty-one jurisdictions, and Kalshi legality by state indexes every state with a court record in one line each.

What follows, and where it comes from

Arizona signed the 37-state brief. The rest of this page is Arizona specific. Where a claim rests on reporting rather than on a document we read ourselves, it says so at that point rather than in a footnote.

The sequence, as reported

Kalshi sued in federal court in March 2026 against Arizona's gaming director and the attorney general, arguing federal law preempts state regulation of contracts traded on a designated contract market. The CFTC and the United States filed their own action on 2 April 2026. The court first refused Kalshi's own request for a preliminary injunction, on the ground that the Anti-Injunction Act barred it from stopping an ongoing state prosecution. It then granted the federal government's request, and the order issued on 5 May 2026.

Three preemption theories, all resolved against the state

On field preemption, the court found the Commodity Exchange Act's grant of exclusive jurisdiction to the CFTC necessarily denies jurisdiction to others, with a framework so pervasive that it left no room for the States to supplement it. On conflict preemption, it held Arizona's enforcement creates the inconsistent regulatory patchwork Congress intended to avoid. On impossibility, it held CFTC rules requiring impartial access conflict with an Arizona law criminalising event wagering without state licensure.

The court expected to be tested

The opinion acknowledged the decision would likely be tested promptly by the Court of Appeals. It has been: the appeal is before the Ninth Circuit, argued as KalshiEX LLC v. Assad. Anything on this page about Arizona's position is provisional until that comes down.

Why Arizona and Connecticut point opposite ways

Arizona is the clearest example of why a single national answer to this question does not exist yet. A federal court in Arizona held the CEA likely gives the CFTC exclusive jurisdiction over these contracts. Three months later a federal court in Connecticut held the opposite way on the threshold question, finding sports event contracts are not swaps at all. Both are federal district courts. Pages that give you one national verdict are choosing which of those to ignore.

The provisions in play

Section numbers are given so you can look them up. Where we have not read the provision directly, the sources list says so.

What we could not verify

• The order itself. We did not read the District of Arizona opinion. Everything above comes from law-firm commentary on it, read direct on 20 Aug 2026, and the phrases describing the holdings are that commentary's characterisation rather than our reading of the court's words.
• The docket numbers and the case caption of the district court actions. Not retrieved.
• The twenty-count criminal information, its counts and its current status.
• The Ninth Circuit outcome, which had not issued when this page was written.

Questions people actually type

Is Kalshi legal in Arizona? There is no yes or no here that would be honest. This page sets out what Arizona has actually done, what its law says, and what a court has or has not decided, so you can see the state of play rather than a verdict nobody has issued.

Has Arizona taken action against Kalshi? The section above answers this for Arizona specifically. Across the country, reporting we read describes fifteen states having sued, investigated or sent cease-and-desist orders over gambling licensure. The states differ, and a page that gives one national answer is flattening that.

Does the CFTC designation settle it? No. Kalshi is a CFTC-designated contract market and nobody disputes that. Whether the designation displaces state gaming law is the contested question, argued through 7 U.S.C. section 2(e) and the clear-statement rule in Whitman, 531 U.S. 457, 468 (2001). Two federal district courts have answered it differently.

Can I be prosecuted for trading in Arizona? We are not lawyers and this is not legal advice. The filings we read are about whether the exchange may offer the contracts, not about individual traders. If that is your real question it is one for someone licensed to answer it in Arizona.

Is the app blocked in Arizona? We have not tested it. Geofencing is a platform setting that changes without notice and is a different question from legality.

How many states are arguing this? Thirty-seven states plus the District of Columbia signed the brief, which is 38 jurisdictions, and Massachusetts is separately the party bringing the case. The full signature block is on the state legality hub.

What this page is not

It is not legal advice and we are not lawyers. It is a reading of public documents and reporting, all linked, so you can check it yourself.