Amkor Technology (AMKR) shares plummeted 7.75% in Tuesday's pre-market trading session, following the release of its third-quarter earnings report and the announcement of a significant leadership change. Despite surpassing analyst expectations for Q3, the company's disappointing fourth-quarter guidance and news of the CEO's impending retirement have overshadowed the positive results.

For the third quarter, Amkor reported earnings of $0.51 per share, beating the analyst consensus estimate of $0.43 and showing a 4.08% increase from the same period last year. The company's quarterly sales reached $1.987 billion, surpassing the expected $1.932 billion and marking a 6.71% year-over-year increase. However, investors seemed more focused on the company's forward outlook.

Amkor's fourth-quarter guidance fell short of market expectations, projecting earnings between $0.38 and $0.48 per share on net sales of $1.78 billion to $1.88 billion. This outlook is below analyst expectations of $0.42 per share and $1.86 billion in revenue. Adding to investor concerns, the company announced that CEO Giel Rutten intends to retire at the end of the year, with COO Kevin Engel set to take the helm on January 1, 2026. Furthermore, Amkor increased its full-year 2025 capital expenditures to approximately $950 million, which may have contributed to the negative sentiment.