Coherent Corp. (COHR) shares plunged 5.14% in after-hours trading on Wednesday, reversing a sharp 8.82% gain during the regular session. The stock fell as investors booked profits following the release of fiscal fourth-quarter results that exceeded analyst expectations but failed to ignite further buying.

The company reported adjusted earnings of $1.74 per share on revenue of $2.05 billion, both surpassing consensus estimates. Strong demand in the datacenter and communications segment drove the 34% year-over-year revenue increase. For the first quarter of fiscal 2027, Coherent issued an outlook calling for revenue of $2.2 billion to $2.4 billion and adjusted EPS of $1.85 to $2.05, also above analyst forecasts at the time of the report.

Despite the beats, the after-hours sell-off suggested that the robust results were largely priced in after the stock's significant intraday run-up. Traders engaged in a classic "sell-the-news" reaction, locking in gains from the pre-earnings rally. Coherent shares had already surged more than 200% over the past year, leaving elevated valuation multiples that raised the bar for upside surprises.