United Microelectronics' stock fell 5.11% during night session trading, marking a significant decline for the semiconductor foundry.

The price movement comes ahead of the company's first-quarter 2026 earnings report scheduled for April 29. According to earnings previews, while revenue is expected to increase by 3.18% year-over-year to $1.93 billion, adjusted earnings per share are projected to decline by 20% to $0.12. EBIT is also forecasted to decrease by 5.94% year-over-year, indicating potential margin pressures despite top-line growth.

Analyst sentiment has been mixed, with one major broker upgrading the stock from Underweight to Equal-weight on April 20, while maintaining a neutral overall stance. The company's initiatives in AI-related optical interconnects through partnerships with HyperLight and Jabil are seen as long-term growth drivers but are not expected to contribute materially to near-term revenue.