Major Banks Granted Summary Judgment in LIBOR-Based Antitrust Litigation Case

On September 25, 2025, Judge Naomi Reice Buchwald of the US District Court for the Southern District of New York rejected all remaining claims in a long-running multidistrict litigation accusing sixteen major banks of a conspiracy to suppress LIBOR. Plaintiffs alleged that banks conspired to suppress LIBOR in order to “project financial strength.”

Judge Buchwald granted summary judgment to all defendant banks and decertified the plaintiff class. The court’s ruling—which disposed of all remaining antitrust, fraud, and other claims—relied heavily on economic analysis and the plaintiffs’ failure to prove any reliable evidence of LIBOR suppression despite 14 years of extensive discovery that included millions of documents and dozens of depositions. Judge Buchwald described the alleged conspiracy as “economically senseless.”

Compass Lexecon Senior Managing Director Professor Dennis Carlton served as an expert for JPMorgan Chase & Co. Professor Carlton provided detailed critiques of plaintiffs’ claims generally and specifically regarding JPMorgan. Judge Buchwald found that the asserted conspiracy was economically senseless because defendant banks did not need to participate in a conspiracy to signal financial strength, as alleged by plaintiffs. Further, plaintiffs’ experts failed to provide systematic evidence of suppression. Judge Buchwald’s reasons for dismissing the plaintiffs’ claims and precluding plaintiffs’ experts’ testimony echo Professor Carlton’s criticisms.

Professor Carlton was supported by a Compass Lexecon team led by Andria van der Merwe that included Joseph Goodman, Theresa Sullivan, and David Gross.

We worked closely with Abram Ellis, Alan Turner, Joshua Hazan, and Rachel Sparks Bradley from Simpson Thacher & Bartlett LLP.