SES AI’s stock fell about 36.8% on March 5, 2026, the day after the company reported logistics constraints and issued full-year 2026 revenue guidance of $30 million to $35 million. That figure came in materially below market expectations.
Berger Montague PC, a plaintiffs’ law firm based in Philadelphia, announced a class action against SES AI Corporation (NYSE: SES) for investors who bought or acquired its securities between January 29, 2025 and March 4, 2026. Investors who want to be appointed lead plaintiff must apply to the court by June 26, 2026.
What the suit alleges
SES AI, based in Woburn, Massachusetts, develops hybrid lithium-metal batteries for electric vehicles and other high-performance uses. The suit says that throughout the class period the defendants repeatedly overstated the company’s business prospects. It accuses them of promoting “phantom” or circular deals and of inflating expected revenue from partnerships with no real substance, while hiding operational constraints and weakening demand.
Outside scrutiny came first. On December 9, 2025, Wolfpack Research published a report alleging that SES AI leaned on questionable counterparties and “phantom deals” to cover for weakening fundamentals. The report, in the complaint’s words, cast serious doubt on the economic substance of the company’s partnerships.
The March 4 disclosure followed about three months later.
The firm
Berger Montague describes itself as a firm focused on complex civil litigation, class actions and mass torts in federal and state courts. It says it has recovered over $50 billion for clients and classes over more than 55 years, and counts more than $2.4 billion in post-trial judgments in 2025 alone. It is headquartered in Philadelphia, with offices in cities including Chicago, San Francisco, Toronto and Washington.
Investors who want details on their rights can contact the firm. The allegations are claims in a lawsuit and have not been decided by a court.
