Micron Technology (MU) stock soared 6.78% in pre-market trading on Tuesday, as a confluence of positive catalysts fueled a sharp rebound from the prior session's steep decline.

The rally was driven by several key developments. Moody's upgraded Micron's senior unsecured bond rating to BAA1 with a stable outlook, reflecting the chipmaker's significantly strengthened financial position amid robust AI-driven demand for memory chips. Separately, Taiwan's Powerchip Semiconductor Manufacturing Corp (PSMC) confirmed that its cooperation with Micron will proceed as planned despite the recent passing of its chairman, easing concerns about potential disruptions to their long-term contract manufacturing deal for high-bandwidth memory (HBM) chips. Additionally, a newly released Counterpoint Research report showed that Micron's DRAM market share by revenue reached 25% in the second quarter, up from 22% in the first quarter, positioning the company to potentially overtake SK Hynix as the world's second-largest DRAM supplier. The report also noted that Micron's DRAM revenue has surged roughly fivefold since the second quarter of 2025.

Further supporting the bullish sentiment, industry sources indicated that Micron, Samsung, and SK Hynix have already completed the allocation of part of their 2027 production capacity ahead of schedule, underscoring the persistent tightness in the memory market driven by AI server demand for HBM and advanced DRAM products.