Ciena Shares Plunge 13% as Tepid Outlook Overshadows Earnings Beat

Ciena, founded in 1992 and headquartered in Maryland, is a global optical networking equipment provider whose products include high-speed fiber-optic systems, network switches and telecommunications equipment. AI computing is driving demand among cloud providers for data-center interconnections, making optical networking critical to overcoming transmission bottlenecks. Ciena has also secured orders from a major cloud customer for its multi-rail networking solution.

Ciena reported fiscal second-quarter revenue of $1.57 billion for the period ended May 2 on June 4, 2026, up 40% from a year earlier. Adjusted earnings were $1.64 per share, with both figures beating expectations. The company forecast full-year revenue of $6.3 billion, plus or minus $100 million, but raised its operating-expense outlook to $1.59 billion–$1.63 billion. Its shares fell 13.66% that day to close at $535.63.