Corning (GLW) shares plummeted 19.29% in pre-market trading on Tuesday, as investors reacted sharply to the company’s third-quarter sales outlook. While the specialty glass and optical networking giant reported second-quarter results that exceeded analyst expectations, the provided guidance failed to satisfy the market’s elevated expectations for an AI-driven growth trajectory.

The company posted second-quarter adjusted earnings of $0.78 per share, beating the consensus estimate of $0.76, with core sales growing 17% year-over-year to $4.74 billion, also topping forecasts. The robust performance was fueled by a 32% surge in its Optical Communications segment, driven by strong demand for generative AI-related products.

However, for the third quarter, Corning forecasted core sales in the range of $4.9 billion to $5.0 billion. Although this represents an approximate 16% growth, the midpoint of the guidance came in slightly below the Wall Street consensus of roughly $5.0 billion. The top end of the forecast merely matched analyst expectations, which was seen as a disappointment given the stock’s nearly 100% year-to-date gain leading into the report. Investors seized on the in-line guidance to lock in profits, sending the stock and its optical networking peers sharply lower in the pre-market session.