Seagate Technology PLC (STX) shares tumbled 6.34% in trading on Tuesday, following the release of its fourth-quarter earnings report and first-quarter guidance. Despite beating expectations for Q4, the company's weak outlook for Q1 2026 has spooked investors, reflecting ongoing challenges in the personal computer market.

The data storage giant reported Q4 adjusted earnings per share of $2.59, surpassing the analyst consensus of $2.45. Revenue for the quarter came in at $2.44 billion, slightly above the estimated $2.43 billion. These results marked a significant improvement from the same period last year, with earnings more than doubling and revenue increasing by 29.5%.

However, Seagate's forecast for the first quarter of fiscal 2026 fell short of Wall Street expectations. The company projects Q1 adjusted EPS of $2.30 (plus or minus $0.20) on revenue of $2.50 billion (plus or minus $150 million). This guidance is below analysts' projections of $2.33 EPS on revenue of $2.51 billion. The company cited weak demand for its storage devices amid ongoing uncertainty in the personal computer market as a key factor influencing its conservative outlook.

CEO Dave Mosley commented on the results, stating, "Seagate's strong FQ4 performance underscores our commitment to profitable growth, marked by a 30% year-over-year revenue increase, record gross margin, and non-GAAP EPS expanding to the top of our guidance range." However, the market's reaction suggests that investors are more concerned about future growth prospects in the competitive data storage market than past performance.