Is Underdog Predict legal in Massachusetts?

Two Underdog companies filed the complaint in the U.S. District Court for the District of Massachusetts on September 8, 2026 (p.1). They are Underdog Exchange DCM, Inc. and UDM, LLC, which does business as Underdog Predict. The case is Underdog Exchange DCM, Inc. v. Campbell, No. 1:26-cv-14098.

The defendants are Attorney General Andrea Joy Campbell and the Gaming Commission's executive director and five commissioners. Each is sued in an official capacity (p.1; ¶¶18-24, p.8).

What does Underdog say the threat is?

Underdog says it began offering its event contracts to users located in Massachusetts on September 4, 2026 (¶30, p.10). It says it "now faces the imminent threat" that the officials will enforce the state's gambling and sports wagering laws against it (¶3, p.3).

It pleads three counts: express, field and conflict preemption (pp.37-41). Each rests on one argument. Underdog says the Commodity Exchange Act gives the CFTC exclusive jurisdiction over trading on federally designated exchanges.

Which Massachusetts laws does Underdog challenge?

The list includes Chapter 23N, the sports wagering law, and the definition of illegal gaming in Chapter 4. It also names Chapter 271, the Gaming Commission's regulations, and Chapter 93A, the consumer protection law (¶95, pp.38-39).

What does Underdog ask the court to do?

The complaint asks for two things (Prayer for Relief, pp.41-42). The first is a declaration that those laws, "or any other state laws pertaining to gambling or wagering," are preempted as applied to Underdog's exchange and its trading on designated contract markets. The second is a permanent injunction barring the officials from enforcing them.

The complaint does not itself ask for a preliminary injunction or a restraining order. These are Underdog's claims, and we found no ruling on them.

Underdog Exchange DCM, Inc. is a Delaware corporation based in Brooklyn. It operates a designated contract market, an exchange the CFTC regulates (¶16, p.7). The complaint says the CFTC designated it on September 5, 2025, under its earlier name, Aristotle Exchange DCM, Inc. Underdog says it acquired the company in March 2026, and the company took its current name on August 31, 2026 (¶28, p.9).

UDM, LLC is a Delaware company, also based in Brooklyn. The complaint calls it a futures commission merchant regulated by the National Futures Association and the CFTC, offering event contracts traded on other exchanges (¶17, pp.7-8). It dates that registration to January 9, 2026 (¶27, p.9).

Underdog's Predict page, read on October 31, 2026, names the exchanges behind its event contracts. They include its own exchange, Kalshi and Crypto.com | Derivatives North America. No other Underdog company is a party to the case.

We found no order, cease-and-desist letter or lawsuit by the attorney general or the Gaming Commission that names an Underdog company. The complaint does not describe one either. It rests the threat it alleges on what the officials have done to others and said in public (¶¶81, 85, pp.32-35).

The Gaming Commission's letter to licensees

The Gaming Commission document we read is its November 13, 2025 letter to "All Sports Wagering Operators." It tells the state's sports wagering licensees they are "prohibited from offering sports-related event contracts in Massachusetts, directly or via an affiliate, related business entity, or other association" (p.1). It warns that the Commission "may take steps up to and including revocation of your license" (p.1).

A footnote says the Commission will not, for now, speak to event contracts offered outside Massachusetts or "event contracts generally" (p.1, n.1). The letter does not name Underdog.

The attorney general's case against Kalshi

Underdog also points to the attorney general's case against Kalshi. Its complaint says the Superior Court enjoined Kalshi's sports contracts on February 6, 2026. It says a single justice of the Appeals Court stayed that order on February 17. It says the Supreme Judicial Court heard argument on May 4 and had not decided when Underdog filed (¶¶75-76, pp.27-28).

Where that case stands now is in is Kalshi legal in Massachusetts?. The attorney general's releases are on mass.gov, which refused our scripted reads. We quote the state only from documents we read.

We could not read the docket past the complaint. So we don't know whether the officials have answered or moved to dismiss, which judge has the case, or whether any date is set. We found no order in it.

Underdog's complaint lists three earlier suits against the same officials in the same court (¶78, pp.29-30):

• Robinhood Derivatives, LLC, No. 1:25-cv-12578, filed September 15, 2025, and on appeal as First Circuit No. 26-1257 when Underdog filed.
• QCX LLC, which does business as Polymarket US, No. 1:26-cv-10651, filed February 9, 2026.
• Ludlow Exchange, LLC, which does business as Novig, No. 1:26-cv-13615, filed August 7, 2026.

Robinhood's case is covered in is Robinhood legal in Massachusetts?. Kalshi’s Supreme Court tracker follows the preemption question in other states.

We found no order that stops Underdog Predict in Massachusetts. Underdog says it has offered event contracts to users there since September 4, 2026 (¶30, p.10).

Its Predict page lists no states. Its disclaimer for Crypto.com contracts says a user must be 18 or older and "present in a state where Underdog Predict operates." We found no Underdog page saying whether Massachusetts is one.

What about withdrawals and open positions?

No filing we read addresses withdrawals, deposits or open positions for Massachusetts users. Underdog argues that if it had to stop in Massachusetts, some traders could be stuck. In its words, a trader could open a position outside the state, travel there, and "lose the ability to close or expand" it (¶10, p.6). That is Underdog's argument about a cutoff that no court has ordered.

Underdog's suit asks who may regulate its event contracts in Massachusetts, and a state gambling ruling, if one comes, is not a ruling on federal tax. How event contract trades are reported on a federal return is in how to file Kalshi taxes.