Coherent shares plummeted 5.22% during intraday trading on Thursday, extending earlier pre-market losses as investors locked in profits following a sharp rally earlier this week. The stock had surged over 15% since August 4, driven by reports that the U.S. Federal Communications Commission was drafting measures to ban imports of new Chinese optical transceiver modules to protect AI data center infrastructure.

The rapid accumulation of unrealized gains triggered significant selling pressure, with the stock already down 3.1% in pre-market action. The decline reflects short-term profit-taking rather than any deterioration in the company's fundamentals, as institutional views remain broadly positive ahead of Coherent's upcoming fourth fiscal quarter earnings report.

Coherent is scheduled to report earnings on August 12, with consensus expectations for revenue of approximately $19.86 billion, up 31.65% year-over-year, and adjusted EPS of approximately $1.62, up 76.71% year-over-year. Sector peer Corning also declined 2.44%, reflecting broader weakness in the electronic components space.