Polymarket has initiated legal proceedings in the U.S. District Court for the District of Massachusetts, aiming to prevent the state from implementing its gambling regulations against the company’s sports prediction contracts.

The lawsuit names Massachusetts Attorney General Andrea Joy Campbell along with state gaming officials as respondents, asserting that federal jurisdiction supersedes state power in the regulation of prediction markets.

This action follows a recent decision from a Massachusetts state judge who chose not to suspend an initial ban on Kalshi’s sports event contracts while the company pursues an appeal. The judge concluded that Kalshi must comply with state gaming laws and obtain a license to provide sports contracts in Massachusetts, dismissing claims that federal regulations negated state authority.

Polymarket expressed that the Massachusetts case against Kalshi presents an “imminent and direct” risk of enforcement actions impacting its platform. The company cautioned that such actions could lead to irreversible damage by destabilizing operations, fragmenting its national market, and forcing it to “choose between its federal right to function nationally or yielding to unlawful state pressure.”

Within its filing, Polymarket aims to avert “imminent and irreparable harm resulting from Massachusetts’s enforcement of state gambling regulations targeting federally regulated derivatives exchanges – a move Congress has explicitly prohibited.

The platform characterized any state intervention against prediction markets as “without merit” and contended that punitive actions would diminish liquidity, jeopardize banking and commercial ties, and erode user confidence.

“Immediate judicial action is crucial to uphold Congress’s directives, maintain the integrity of the federal market framework, and protect the rights of users across the country,” Polymarket asserted in its complaint.

The company’s stance aligns with the industry’s belief that prediction markets fall under the sole jurisdiction of the Commodity Futures Trading Commission. Polymarket, Kalshi, Crypto.com, and other platforms have argued that CFTC oversight of event contracts overrules state-level gambling regulations.

Neal Kumar, Polymarket’s chief legal officer, confirmed the lawsuit via social media, directly linking it to the Kalshi decision. “Congress has granted the CFTC, not individual states, exclusive control over event contracts,” Kumar commented. “These are national markets with significant issues that must be adjudicated in federal court.”

Today, we filed a lawsuit against Massachusetts in federal court. Congress granted the CFTC, and not states, exclusive jurisdiction over event contracts.

These represent national markets with crucial issues that need resolution in federal court 🧵

— Neal Kumar (@HereComesKumar) February 9, 2026

Kumar criticized state authorities’ attempts to stifle prediction markets using legal action. “Rushing to state court to attempt to shut down Polymarket US and other prediction marketplaces fails to amend federal law – and states such as MA and NV that have pursued this route will overlook a remarkable opportunity to nurture future markets,” he stated.

“As always, we remain open to discussions with other states while federal courts deliberate on these pivotal topics. We advocate for our users.”

Polymarket has previously encountered challenges in various jurisdictions. In Nevada, a judge ruled in favor of the state in a case against the platform, prompting Polymarket to withdraw from that jurisdiction. On the same day as the Massachusetts ruling regarding Kalshi, a federal judge in Nevada denied Coinbase’s petition for an order protecting it from enforcement actions initiated by the state’s attorney general and gaming commission.

Robinhood, a collaborator with Kalshi and another prediction market platform, is also seeking a preliminary injunction in federal court in Massachusetts to prevent Campbell from compelling compliance with the state’s sports gambling licensing framework.

Polymarket is being represented by Gibson Dunn & Crutcher LLP and Mintz Levin Cohn Ferris Glovsky & Popeo PC. The case is QCX LLC v. Campbell, No. 1:26-cv-10651, complaint filed Feb. 9, 2026.