Lumentum’s stock suffered a 5.05% plunge over the 24-hour period, as a broad sell-off in optical communications stocks intensified amid mounting doubts about the pace of AI infrastructure spending.

The decline was triggered by sector-wide concerns after Corning provided Q3 revenue guidance of $4.9–5.0 billion, which came in at or below consensus estimates. This sparked a sharp rotation out of AI hardware names, with investors questioning the near-term visibility of data center capex demand. Corning tumbled nearly 19%, Coherent dropped over 12%, and Ciena fell more than 10% during regular trading, dragging Lumentum down over 8% in the same session. The weakness persisted in after-hours trading, as Lumentum extended its losses.

Optical components and high-speed interconnect demand are highly sensitive to AI data center investment cycles, leaving the sector especially vulnerable when capital expenditure momentum is called into question. The market’s cautious reassessment of the AI hardware narrative continues to weigh on Lumentum and its peers.