Micron falls 3.9% as China's CXMT claims progress on denser DRAM aimed at servers

MU fell about 3.9% on Monday to close near $989, leading a broad memory selloff after China's ChangXin Memory Technologies (CXMT) flagged progress on a next-generation DRAM design, per SentiSense market data. In morning trading Micron and SK Hynix's U.S.-listed shares were each down about 4% and WDC about 2%, while the Roundhill Memory ETF fell about 4% with the S&P 500 roughly flat.

CXMT president Cao Kanyu told an industry event in Shanghai over the weekend that the company has made progress on a 4F² cell layout, denser than the 6F² structure used in mainstream commercial DRAM, and plans a new generation of DDR5 server memory modules based on it by the end of 2026, Investing.com reported, citing the South China Morning Post. CXMT has not disclosed detailed specs or a launch date. The architecture is not unique to CXMT: SK Hynix published its own 4F² roadmap in 2025 and Samsung reportedly targets mass production with it by 2028. In Seoul, before the U.S. open, Samsung fell 3.6% and SK Hynix 3.4%.

The selling spread beyond DRAM makers. SNDK fell about 6% and STX about 4% in early trading even though neither company makes DRAM, a sign that memory and storage are trading as one AI hardware complex, 24/7 Wall St. reported. Micron traded around the $980 area that technical traders had flagged as support, defined by its 200-period moving average at $979.80.

The drop comes against strong fundamentals. Micron reported fiscal fourth-quarter revenue of $54.23 billion against estimates of $50.97 billion and guided first-quarter revenue to $61.5 billion at the midpoint, and the stock was still up about 245% year to date on Monday morning. Separately, Micron's board raised its discretionary buyback authorization to $35.16 billion, though CHIPS Act funding terms bar repurchases until Dec. 9, 2026, Investing.com reported. What to watch: whether CXMT ships and qualifies a 4F² server product with customers, which has not happened yet, and whether DRAM contract pricing shows any effect before Micron's next report.