Micron Technology stock ends the day up 3.89 percent at the close

Micron Technology stock closed on the Nasdaq at USD 1,015.80 on September 21, 2026, gaining 3.89 percent from the prior session. Compared with the broader U.S. market, Micron outperformed major indices as semiconductor and memory names benefited from continued optimism around AI-related demand, according to a sector recap from Bitget.

September 21, 2026 in numbers

Micron Technology Inc. (ISIN US5951121038, Nasdaq: MU) advanced after traders focused on memory-chip exposure to the AI cycle and ahead of the company’s upcoming quarterly results, with semiconductor peers also moving higher as highlighted in a market summary from TradingKey. Per exchange data cited in the Bitget overview, Micron’s 3.89 percent rise left the stock ahead of major U.S. indices on the day, while the Philadelphia Semiconductor Index gained about 2.78 percent. The move added to a strong year-to-date performance that has seen Micron become one of the leading AI memory plays in the chip sector.

After the bell and the next earnings date

In after-hours trading on September 21, 2026, Micron was referenced around recent levels in commentary on AI-chip leaders, with investors watching for further signals from index futures and sector peers as extended trading continued. Looking ahead, Micron plans to report its fiscal fourth-quarter 2026 results after the close on September 30, 2026, with a post-market conference call, according to an earnings preview from InsiderFinance. That preview notes Micron’s guidance for revenue of 50.0 billion U.S. dollars plus or minus 1.0 billion and a non-GAAP gross margin near 86 percent for the quarter, making the upcoming report a key catalyst for Micron Technology stock and the broader AI memory cycle.