United Microelectronics (UMC) stock plummeted 6.47% during intraday trading on Monday, reflecting significant selling pressure ahead of the company's upcoming financial results.

The decline comes as market consensus expects UMC's quarterly earnings, scheduled for release soon, to show only modest revenue growth of 3.18% year-over-year alongside a projected 20% decline in adjusted earnings per share. Additionally, the company's first-quarter capacity utilization guidance is below the industry average, signaling potential profitability headwinds.

Earlier market optimism about UMC potentially entering the 2D NAND foundry business has been tempered by supply chain analysis highlighting significant challenges in talent acquisition, technology integration, and equipment readiness. Broader pressures on the mature-node semiconductor segment from AI-driven demand shifts and rising costs have also contributed to the negative sentiment.