STMicroelectronics N.V. (NYSE: STM) shares experienced a pre-market plunge of 5.01% on Thursday, following the company's release of its fourth-quarter and full-year 2025 financial results.

The semiconductor leader reported a non-GAAP earnings per share of $0.11 for Q4 2025, a steep 70.3% decline from the $0.37 per share reported in the prior-year period. This result missed analyst consensus estimates, which ranged from $0.14 to $0.27 per share. On a U.S. GAAP basis, the company posted a net loss of $30 million, or $0.03 per diluted share.

Investor sentiment was further impacted by the company's first-quarter business outlook, which forecasts a gross margin of approximately 33.7%, including about 220 basis points of unused capacity charges. The significant year-over-year drop in profitability, coupled with the earnings miss, drove the sharp negative reaction in pre-market trading.