COHERENT's stock experienced a significant 24-hour plunge of 5.05%, reflecting heightened volatility in the optical communication sector during the extended trading period.

The decline comes despite recent positive developments for the company, including the groundbreaking ceremony for its Texas indium phosphide factory expansion attended by NVIDIA CEO Jensen Huang and confirmation of a $50 million CHIPS Act subsidy. NVIDIA had previously invested $2 billion in Coherent with a long-term supply agreement.

Market analysts point to a bearish CPO (Co-Packaged Optics) research report published by SemiAnalysis as the primary driver of sector-wide selling pressure. The report argues that large-scale CPO commercial deployment faces significant delays until 2028-2029, citing core bottlenecks including low optical engine yield rates, high co-packaging integration difficulty, and unfavorable system-level cost economics. This research has intensified bull-bear divergence in the optical communication sector, dragging down peers including Corning and Vishay Intertechnology.