ON Semiconductor's stock experienced a significant after-hours plunge of 6.39% following the release of its fourth-quarter and full-year 2025 financial results. The sharp decline came as investors reacted to the company's latest earnings report.

The semiconductor maker reported Q4 revenue of $1.53 billion, which slightly missed the analyst consensus estimate of $1.54 billion. More notably, the company's net income for the quarter dropped 52% year-over-year to $181.8 million. For the full year 2025, ON Semiconductor's net income attributable to shareholders plummeted to $121.0 million, representing a dramatic 92.3% decline from the previous year.

While the company's adjusted earnings per share of $0.64 beat the $0.62 estimate, the revenue miss combined with the substantial profit deterioration appears to have driven negative investor sentiment. The company also provided its Q1 2026 revenue outlook of $1.435-$1.535 billion, which will be closely watched by market participants moving forward.