US optical communications stocks open lower; Lumentum falls over 3%

The move looks sector-wide rather than company-specific, since Lumentum, Coherent, Corning and Marvell all opened weaker together — a pattern that usually points to a shared read-through on demand expectations for optical components rather than any single firm's news. Because these names sit in the supply chain for datacenter and telecom buildouts, their early trading is often treated as a proxy for sentiment on that spending. Whether the decline holds through the session or fades is the open question.