U.S. optical communications stocks fell sharply at the market open, with Corning down more than 9%. Marvell Technology, Lumentum and Coherent each dropped more than 8%, while Credo and Ciena declined more than 6%, according to MSX.COM data. Software shares moved in the opposite direction: ServiceNow rose more than 5%, Adobe gained nearly 4%, Salesforce climbed nearly 3%, and Microsoft edged higher.