The Antitrust Attorney Blog
Author: Luis Blanquez
A federal judge in New York recently certified two classes of cryptocurrency buyers against Tether and Bitfinex. If you issue a stablecoin, run an exchange, or make markets in digital assets, that sentence should get your attention. The case, In re Tether and Bitfinex Crypto Asset Litigation, has been running since 2019, and the plaintiffs say the defendants inflated crypto prices by hundreds of billions of dollars. In February 2026, the court said those buyers can sue as a class. In July, the Second Circuit upheld that ruling.
Class certification is the moment a manageable lawsuit becomes an existential one. Before certification, a defendant faces a handful of named plaintiffs and their individual losses. After it, the defendant faces the aggregated claims of everyone who bought in the market during the class period. The dollars change by orders of magnitude, and so does the pressure to settle. That asymmetry is the whole game in class litigation, and it is why the certification order is often the fight that decides the value of the case.
Here, the certification order is actually more useful to defendants than the headline suggests. The plaintiffs got their class, but the court excluded a key piece of their expert analysis, cut both classes down, and set aside the central causation question for a later summary judgment fight.
Before we discuss this in more detail, you should download our Antitrust Guidelines for Companies Using Blockchain Technology.
The Complaint: A Manipulation Theory Built on a Stablecoin
The operative pleading is the Amended Consolidated Class Action Complaint, filed in June 2020.
Tether issues USDT, a stablecoin it marketed as backed one-to-one by U.S. dollars held in reserve and redeemable on demand. The plaintiffs allege that was a lie—that Tether created USDT out of thin air, without the dollars to back it, and moved the unbacked coins to its affiliated exchange, Bitfinex, without paying for them.
Through an anonymous trader, the defendants allegedly used the debased USDT to make large, well-timed purchases of Bitcoin and other crypto commodities precisely when prices were falling. The market read those purchases as real demand and stopped the slide, which let the defendants convert coins they had created for free into assets with genuine value. The complaint ties the scheme to the 2017 run-up—Bitcoin climbing from roughly $800 to $20,000 in a year—and to the roughly $450 billion in value that evaporated when the bubble burst in 2018. Plaintiffs pleaded claims under the Sherman Act, the Commodity Exchange Act, RICO, common law fraud, and New York’s consumer protection statute.
The lesson in the complaint is that the plaintiffs anchored an ambitious economic theory to concrete, provable conduct: specific issuances of USDT, specific representations about reserves, and specific trades. Regulators had already questioned Tether’s reserve claims. All that together provided the complaint with teeth, which is exactly what most crypto complaints lack and exactly what let this one survive.
The Motion to Dismiss: The Theory Narrows to Antitrust and Commodities
In September 2021, the court granted the motion to dismiss in part and denied it in part.
The court threw out the RICO claims, holding that the causal chain between the alleged racketeering and the plaintiffs’ losses was too indirect to satisfy proximate cause. It dismissed the conspiracy to monopolize count and the New York General Business Law claim.
What survived was the core: monopolization and attempted monopolization under Section 2 of the Sherman Act, the restraint of trade claim under Section 1, and market manipulation and aiding and abetting under the Commodity Exchange Act.
For defendants, the motion to dismiss ruling hides a warning: The claims that fell were the ones that depended on long, attenuated causal chains or strained standing theories. The claims that stuck were the ones tied most directly to the alleged conduct and its market effect. Defendants who treat the motion to dismiss as their last, best chance to end the case tend to be disappointed—the leverage often arrives later, at certification and summary judgment.
Class certification: Only a Partial Win for Plaintiffs
For certification, the plaintiffs relied on an economic expert who offered three analyses: (i) an event study meant to show that USDT issuance caused Bitcoin’s price to rise; (ii) a regression model linking changes in the outstanding volume of USDT to Bitcoin prices; and (iii) an overcharge model quantifying the inflation. The defendants moved to exclude the expert and opposed certification only on adequacy and predominance.
The court excluded the event study because the statistical test behind it assumed independent data points that were not independent. But it kept the regression and overcharge models, and those were enough. On adequacy, it rejected the defendants’ intraclass conflict theories. On predominance, it made the framing explicit: in antitrust and commodities cases, the defendant’s own conduct is often a common question, so these cases turn on injury, causation, and damages.
Then the court did three things that narrowed the plaintiffs’ win:
First, it held that antitrust injury flows from the overcharge at purchase and used that to cut buyers who paid with other crypto, along with anyone who mined coins, took them through a fork, or received them as gifts—limiting both classes to purchasers who paid with fiat or stablecoins.
Second, it applied the rule that the Commodity Exchange Act does not reach foreign transactions, dropped every futures trade on a foreign exchange, and drew lines around trades on “stateless” exchanges that answer to no regulator.
Third, and most important, it held that whether the alleged debasement actually caused prices to rise is a question for summary judgment, not certification, relying on the Supreme Court’s decision in Tyson Foods v. Bouaphakeo that a failure of proof shared by the whole class is a merits problem.
The court certified two classes running from March 2017 through February 2019 and excluded anyone who bought only on Bitfinex itself.
The defendants asked the Second Circuit to take an interlocutory appeal under Rule 23(f). On July 2, 2026, the court declined. The certification order stands, and the case now moves to summary judgment.
Recommendations for Class Action Defendants
If you face an antitrust lawsuit in the crypto or blockchain industry, focus first on the issues that will most affect exposure and leverage.
Attack the model the plaintiffs actually need, not every model
The defendants knocked out the event study and still lost the motion, because the regression and overcharge models carried the class. Before you spend the money, identify which expert model proves class-wide impact and which proves damages, and aim there.
Treat the class definition as a damages lever, not a technicality.
The most valuable defense work in Tether happened at the class definition stage. Pressing injury and extraterritoriality did not stop certification, but it removed crypto for crypto buyers, miners, fork recipients, gift recipients, and all foreign exchange futures trades. In a market-wide case, shrinking who is in the class can be worth more than any single merits argument.
Save a class-wide causation attack for summary judgment
The court punted the fact of causation for the merits. So, if the plaintiffs’ model cannot show that your conduct actually moved prices, the entire class fails together. Build the certification record and the expert discovery with that summary judgment motion in mind from day one, so the causation gap is teed up and documented before you ever file it.
If you touch reserves or backing claims, build the paper trail now
Tether’s exposure traces directly to public statements about what backed its coin and to regulators who tested those statements. Any company that makes representations about reserves, custody, or backing should assume those statements will be litigated line by line. Document what backs the product and keep the records that prove it.
Map your exchange footprint before you are sued
The court sorted futures trades by where they happened: domestic exchanges in, foreign exchanges out, stateless exchanges resolved exchange by exchange on facts like where trades were matched and whether orders could be revoked. For a crypto business, that means the location of your matching engines, the terms of your user agreements, and the regulatory status of the venues you use are not back-office details—they are the facts that will decide how large a class you face. Know them now, because a plaintiff’s expert will map them for you later.
Weigh a Rule 23(f) appeal—but do not bank on it
Tether and Bitfinex petitioned the Second Circuit for interlocutory review, and on July 2, 2026, the court denied it. Rule 23(f) review is discretionary and rarely granted, here, even when the movant pointed to an excluded expert study. Preserve the option when a certification ruling turns on a clean legal question, but do not build your strategy around it. The summary judgment motion is the stronger card.
The Bigger Picture for Defendants Going Forward
For years, crypto defendants could count on plaintiffs stumbling over the threshold problems of this market: proving manipulation in a decentralized system, establishing that transactions were domestic, showing class wide impact across dozens of assets and venues.
But crypto and blockchain is past the point where defendants can treat class litigation as someone else’s problem. Courts have shown now they will certify when the economics are credible and the class is defined with care.
The Tether case shows both sides of the ledger: plaintiffs can now get a crypto manipulation class certified, and defendants still hold real tools—expert exclusion, antitrust injury and extraterritoriality limits on the class, and a class-wide causation defense held for summary judgment.
Most companies in this space think about litigation risk as a question of whether they will get sued. The better question is what happens at certification, because that is where the exposure is set. The Tether case shows that a well-run defense does not have to defeat certification outright to change the shape of the case. Excluding a model, narrowing a class, and preserving a merits defense can turn a hundred-billion-dollar claim into something far smaller and far more winnable—even when the class gets certified.
Image by WorldSpectrum from Pixabay