Cohu's stock experienced a sharp decline of 20.95% in post-market trading. The semiconductor equipment company's shares plummeted following the release of its fourth-quarter financial results.

The sell-off was primarily driven by a substantial bottom-line miss. Cohu reported an adjusted loss of $0.15 per share for Q4 2025, which dramatically missed the analyst consensus estimate for a profit of $0.06 per share, representing a miss of over 340%. This overshadowed the company's revenue performance, where sales of $122.2 million slightly exceeded expectations and showed a significant year-over-year increase.

Investor sentiment turned negative as the company also reported a GAAP net loss of $22.5 million for the quarter. While providing an outlook for the first quarter of 2026 with sales projected at approximately $122 million, the significant earnings disappointment led to the after-hours plunge.