Overview
Polymarket US’s exchange entity sued Michigan’s Attorney General and Gaming Control Board in March 2026 seeking to block enforcement against its sports event contracts. It lost twice. Judge Paul L. Maloney denied a temporary restraining order in March 2026 and then denied a preliminary injunction on June 17, 2026, in one of two near-identical opinions issued the same day (the other denying Robinhood Derivatives). Read from the opinion itself (ECF No. 41, 34 pp.), the holding has two independent parts. First, the statutory definition of “swap” is ambiguous, and Polymarket US’s products fall outside it: in one prong of a six-part definition of a single derivative type, enacted in a statute passed after the 2008 financial crisis, there is no clear statement that Congress meant to supersede the states’ traditional role in regulating gambling. Second, and independently, even if the products were swaps, the court held it is not clear the federal framework stops states regulating in what it called the porous zone where derivatives and gambling meet.
Polymarket US appealed the same day. In July 2026 the Sixth Circuit denied its motion to consolidate with the Kalshi appeals from Ohio and Tennessee, but ordered that this appeal and Robinhood’s be submitted to the same panel on the same day after briefing. The CFTC filed an amicus brief supporting Polymarket US in August 2026 — the agency backing a private platform against a state in a case it is not a party to.
Changes
Logged September 22, 2026
Timeline
March 2026
Polymarket US sues Michigan’s Attorney General and Gaming Control Board; the court denies a temporary restraining order.
June 2026
Judge Maloney denies a preliminary injunction; Polymarket US appeals to the Sixth Circuit the same day.
July 2026
The Sixth Circuit denies consolidation with the Kalshi appeals but orders this appeal submitted to the same panel, on the same day, as Robinhood’s.
August 2026
Opening brief filed; the CFTC files an amicus brief supporting Polymarket US; the district court stays proceedings pending appeal.
September 16, 2026
Michigan files its appellee brief.
What's next: On appeal at the Sixth Circuit (No. 26-1552). Polymarket US filed its opening brief August 17, 2026, the CFTC filed as amicus August 24, and Michigan filed its brief September 16. Polymarket US’s reply is next, then submission to the same panel as Robinhood’s appeal. District proceedings are stayed pending the appeal.
Parties
Plaintiffs
- QCX, LLC d/b/a Polymarket US
Defendants
- Dana Nessel (Michigan Attorney General)
- Henry L. Williams, Jr. (Executive Director, Michigan Gaming Control Board)
- Jim Ananich (Board Chair), Mark Evenson, Deidre A. Lambert-Bounds, Andrew T. Palms and Joni M. Thrower Davis (Michigan Gaming Control Board)
This page is informational, not legal advice. Nearly every entry in this tracker is a preliminary ruling under appeal. Always verify a platform's current, location-specific eligibility directly with the venue before relying on this page.