This Law Firm Publication by Wiley Rein LLP discusses Genesis Insurance Co. v. Magma Design Automation, Inc., No. 11-15800, (9th Cir. Feb. 5, 2013). In this case before the US Court of Appeals for the Ninth Circuit, the court held that under California law the prior notice exclusion of an excess policy did not bar coverage for securities and derivative litigation where the insured's notice of a related patent infringement action had been held not to comply with the notice-of-circumstances clause of the prior policy. The publication discusses the case's factual background and the court's ultimate legal holdings.