Directors and officers at JPMorgan Chase & Co.—one of the country’s “Big Four” banking institutions—may not be held liable for losses incurred by a trader who became known as the “London Whale,” the Delaware Court of Chancery decided last week, tossing the case under the business judgment rule.

Vice Chancellor Sam Glasscock III, writing a memorandum opinion in Asbestos Workers Local 42 Pension Fund v. Bammann, said a New York court’s decision on the matter was entitled to collateral estoppel effect in the Delaware courts. He granted the defendants’ motion to dismiss the action, which had been brought by JPMorgan Chase shareholders led by a pension fund. Among the defendants in the case was Jamie Dimon, the chairman, president and CEO of JPMorgan Chase.