Underdog Exchange has initiated legal proceedings by filing a case on November 8 in the U.S. District Court for the Western District of Missouri.

The case is currently under the purview of Judge Mary Elizabeth Phillips. Notably, the court docket reflects an entry for a “preliminary injunction” filed on the same date, alongside three applications from out-of-state lawyers seeking to appear in the matter.

However, the complaint itself remains unavailable to the public on the docket. This lawsuit seeks a preliminary injunction to prevent Missouri officials from enforcing what Underdog claims are “preempted gambling statutes” against its federally regulated derivatives markets, as reported by Gaming America.

The court has yet to rule on Underdog’s preemption argument. In September, Hanaway’s office stated that it had dispatched cease-and-desist letters to several companies, including Polymarket, Kalshi, Crypto.com, Novig, Underdog, and Robinhood. They asserted that these companies’ sports event contracts constitute unlicensed sports wagering under Missouri law.

They urged these entities to cease their offerings to Missouri residents until they obtain the necessary licensing from the Missouri Gaming Commission, warning that noncompliance could lead to enforcement actions. Hanaway emphasized, “Companies cannot repackage sports bets as ‘event contracts’ to avoid Missouri law. We will enforce the rules voters approved and protect consumers.”

Her office also raised concerns that many of these companies, Underdog included, either allow underage users to access their services or lack sufficient protections to prevent individuals under 21 from participating. Missouri voters approved sports betting in 2024, and the regulated market officially launched on December 1, 2025, featuring a 10% tax on the gross receipts from sports betting, as confirmed by the attorney general’s office.