Why Is Micron (MU) Stock Up Today? $500B Milestone, HBM4 Vera Rubin Launch Spark 4.5% Rally

Micron Technology (MU) closed the session on March 17, 2026, with a 4.50% gain, ending at $461.69. The rally propelled Micron into the Half-Trillion Club, marking a historic valuation milestone ahead of its fiscal Q2 earnings release. Despite a broad macro environment weighed down by energy-driven inflation and geopolitical tensions, investors are piling into MU as the AI Memory Supercycle enters its most aggressive phase yet.