Shares of Ciena Corporation (CIEN) tumbled 6.77% in pre-market trading on Thursday following the release of its fiscal second-quarter 2025 financial results. The network technology company reported mixed results, with revenue beating expectations but earnings falling short of estimates.

Ciena reported quarterly revenue of $1,130 million, surpassing the IBES estimate of $1,092 million. However, the company's adjusted earnings per share (EPS) came in at $0.42, significantly below the expected $0.52. The adjusted net income for the quarter was $60.7 million, considerably lower than the IBES estimate of $76.1 million.

The disappointing earnings results appear to be the primary driver behind the stock's pre-market plunge. While Ciena's top-line performance was strong, the substantial earnings miss has likely raised concerns among investors about the company's profitability and cost management. The market's negative reaction suggests that investors are focusing more on the bottom-line performance rather than the revenue growth in the current economic environment.