Coinbase, a cryptocurrency exchange, is facing a new class-action lawsuit over allegations of hiding a significant data breach involving insider misconduct and regulatory violations in their UK operations. The lawsuit, filed by investor Brady Nessler in the US District Court for the Eastern District of Pennsylvania, claims that Coinbase's lack of transparency led to financial losses for shareholders who bought COIN stock between April 14, 2021, and May 14, 2025.

The complaint accuses Coinbase of not disclosing a data breach where cybercriminals attempted to extort $20 million after stealing customer data. Although Coinbase stated that less than 1% of its users were affected, the breach was only disclosed after the extortion attempt, causing COIN's stock to drop by 7.2% on May 15, 2025.

Additionally, the lawsuit points out a regulatory issue in Coinbase's UK subsidiary, CB Payments Ltd., which was fined £3.5 million by the UK's Financial Conduct Authority for breaching a regulatory agreement. This incident led to a further decline in COIN stock price by 5.52% on July 25, 2024.

Nessler seeks class certification, financial compensation, legal fees coverage, and a jury trial. Coinbase has not responded publicly to the lawsuit. Despite a slight recovery from the May 15 lows, Coinbase's stock price dropped by 3.23% on May 23, settling at $263.1.