Nevada Cites Massachusetts Kalshi Ruling, Seeks to Shut Down Polymarket

Nevada Files Massachusetts Kalshi Decision as Supplemental Authority

In a filing submitted to the U.S. Court of Appeals for the Ninth Circuit, Nevada notified the court of the recent Massachusetts ruling that granted a preliminary injunction blocking Kalshi from offering sports-related event contracts without state licensure.

In the filing, shared by gaming attorney Daniel Wallach, the Nevada Attorney General’s Office, on behalf of the Nevada Gaming Control Board (NGCB), submitted the ruling as supplemental authority in Kalshi’s pending appeal. It argued that the Massachusetts court’s reasoning directly undermines Kalshi’s request for an injunction pending appeal in Nevada.

According to Nevada, the decision confirms that Kalshi is not likely to succeed on the merits of its claim that federal commodities law preempts state gaming regulation.

Massachusetts Court Rejects Federal Preemption Argument

The Massachusetts court rejected Kalshi’s argument that federal oversight of derivatives markets allowed it to bypass state gambling regulation. It found that the Commonwealth retained authority over sports wagering offered to residents within its borders.

In granting the preliminary injunction, Massachusetts Superior Court Judge Christopher Barry-Smith wrote:

“The Commonwealth is entitled to a preliminary injunction prohibiting Kalshi from offering sport-related event contracts in the absence of the required license under the Sports Wagering Law.”

Nevada cited the ruling to argue that the decision directly undermines Kalshi’s claim that it is likely to succeed on the merits of its appeal in the Ninth Circuit, where the company is seeking to continue operating while the case proceeds.

Additionally, Nevada pointed to the court’s equitable findings to argue that Kalshi failed to demonstrate irreparable harm, weighing against the extraordinary relief the company seeks pending appeal.

Other Courts and States Are Already Citing the Massachusetts Ruling

The Massachusetts injunction is already being cited across multiple active proceedings involving Kalshi and sports prediction markets. Wallach noted that the decision has now been referenced in cases pending in:

• the Southern District of New York
• the Middle District of Tennessee
• the Ninth Circuit

Wallach expects that additional jurisdictions — including Ohio, Connecticut, and the Third Circuit — will likely reference it as well. He has described the Massachusetts decision as having “far-reaching implications.”

Nevada Seeks TRO and Preliminary Injunction Against Polymarket

In a separate enforcement action, Nevada has filed a civil complaint against Polymarket. Also, it simultaneously moved for a temporary restraining order and a preliminary injunction to shut down the platform in the state.

The NGCB’s filing seeks to enjoin Polymarket, along with its agents, employees, and affiliates, from offering “event-based contracts tied to sporting and other events” to persons located in Nevada without obtaining the required gaming licensure.

The complaint and accompanying injunction request ask the court to bar Polymarket from operating what Nevada characterizes as an unlicensed prediction market and derivatives exchange accessible to Nevada residents.

Nevada Signals Broader Enforcement Push on Prediction Markets

Taken together, Nevada’s supplemental filing in the Kalshi appeal and its injunction request against Polymarket affirm a broader regulatory strategy Nevada has been advancing for months. The state is aiming to assert state control over sports-related prediction markets.

With courts in multiple jurisdictions now weighing in, the Massachusetts ruling provides a judicial roadmap for states seeking to resist federal preemption arguments while expanding enforcement against sports-linked prediction markets.

The growing role of the courts comes as Commodity Futures Trading Commission Chair Michael Selig has taken a limited approach to regulating prediction markets. He’s indicated that litigation rather than administrative action will determine their status.