Polymarket and OG.com Sue Arkansas Five Days After It Took Kalshi to Court

Two federally regulated exchanges have sued Arkansas' attorney general and its racing commissioners rather than wait to be the next Kalshi. Arkansas now faces the same race to federal court as Missouri, although neither exchange says the state has written to it.

• Polymarket US and Crypto.com's OG.com sued Arkansas Attorney General Tim Griffin and seven Arkansas Racing Commission commissioners in two federal districts on Monday 9 November
• Both complaints cite Griffin's 4 November state-court suit against Kalshi as proof that enforcement against them is imminent
• Each asks for a declaration that the Commodity Exchange Act preempts Arkansas gambling law as applied to it, and an injunction; neither docket showed a motion for interim relief by Tuesday
• OG.com argues there is no licence it could obtain: Arkansas allows three casino licences, all awarded, and only for wagers placed inside the state
• Underdog's Missouri complaint, now public, says the state told it on 6 November it would bring enforcement proceedings within three days, the same warning Robinhood cited when it sued

Two Exchanges Sue Pre-Emptively After Griffin's Kalshi Suit

QCX LLC, which trades as Polymarket US, filed QCX LLC v. Griffin (No. 1:26-cv-01076) in the El Dorado Division of the Western District of Arkansas on 9 November. The case is assigned to District Judge Timothy L. Brooks. The same day North American Derivatives Exchange, Inc., which trades as OG.com Prediction Markets, filed No. 4:26-cv-01226 in the Eastern District, where it is assigned to District Judge Kristine G. Baker.

Both suits name Griffin and the same seven commissioners in their official capacities: Chairman Alex Lieblong, Mark Lamberth, Steve Anthony, Denny East, Michael Post, John Schmelzle and Steve Landers. Polymarket's complaint calls the body the Arkansas Racing Commission; OG.com's calls it the Arkansas Racing & Gaming Commission.

Neither exchange says it has received a cease-and-desist letter. Both rest the threat of enforcement on Griffin's opinion of 23 October 2025, which concluded that the business model of a contract market such as Kalshi is gambling requiring a licence, and on his consumer protection suit against Kalshi in Independence County Circuit Court. Polymarket adds that Griffin signed the 39-state amicus brief supporting New Jersey's Supreme Court petition in Flaherty v. KalshiEX, and says his actions show "animus toward" prediction markets.

What Each Complaint Asks For

Polymarket's 37-page complaint pleads one count of preemption under the Commodity Exchange Act (CEA), brought under 42 U.S.C. § 1983. It argues express, field and conflict preemption, citing the CFTC's exclusive jurisdiction over contracts traded on designated contract markets and a 1978 provision that excludes contract markets from the suits states may bring to enforce the Act. It seeks a declaration that Amendment 100 to the Arkansas Constitution, the commission's rules and several Arkansas statutes are preempted as applied to it, preliminary and permanent injunctions, and its legal fees. Gibson, Dunn & Crutcher and Little Rock firm Quattlebaum, Grooms & Tull act for it.

OG.com pleads three counts, for express, field and conflict preemption, and asks for a declaration and a permanent injunction covering any Arkansas law "pertaining to gambling, fringe gambling, or online gambling". Its prayer does not ask for a preliminary injunction. The complaint says OG.com, a contract market since 2004, offers more than 50 event contracts and serves Arkansas residents. Skadden, Arps, Slate, Meagher & Flom represents it.

Underdog's Missouri Complaint Is Now Public

No Underdog suit against Arkansas had appeared by Tuesday. Its Missouri complaint, filed on 8 November and since made public, names Underdog Exchange DCM, Inc. and UDM, LLC, which trades as Underdog Predict, as plaintiffs, and Attorney General Catherine Hanaway and six Missouri Gaming Commission officials as defendants. It pleads the same three preemption counts as OG.com and lists three of the Skadden lawyers who appear for OG.com. It says Missouri's 17 September letter set a deadline later extended to 30 October, and that on 6 November the attorney general's office said enforcement proceedings would begin within three days. Missouri's response to Underdog's preliminary injunction motion is due on 23 November.

Arkansas Has Handed the Exchanges Their Standing Argument

A pre-enforcement challenge needs a credible threat, and Missouri has already argued in Novig's case that such a claim is not ripe until the state acts. In Arkansas the exchanges point to an actual enforcement suit against a direct competitor over the same products. OG.com cites the Supreme Court's view that past enforcement against the same conduct shows a threat is not "chimerical". Suing Kalshi first may have made it easier for everyone else to sue Arkansas.

There Is No Arkansas Licence for an Exchange to Hold

OG.com's strongest point may be factual. As its complaint sets out, Amendment 100 allows three casino licences, all awarded, and the commission's rules permit sports wagers only from people physically in Arkansas. A national exchange cannot meet that without breaking the CFTC's impartial access rule, which, as Polymarket's complaint notes, the agency has said bars restricting users by state. The CFTC's geofencing guidance is doing work in these courtrooms even before its 30-day deadline runs out.

One Circuit, Several Courts

The Polymarket and OG.com cases sit in different districts before different judges, just as Missouri's six cases are split between St. Louis and Jefferson City or Kansas City. All of them sit in the Eighth Circuit, which has yet to decide Kalshi's Iowa appeal. Until it does, district judges in two states will decide the same question separately.

Arkansas chose its own court for Kalshi, and the next two exchanges have chosen federal court. Unless the state counter-sues as Missouri did against Novig, the first federal ruling in Arkansas will come on the exchanges' claims, not the state's.