Key Highlights

● MU shares fell 3.88% to $989.04 in Monday’s session, making Micron the most actively traded US stock by dollar value.

● The selling followed a report that China’s CXMT, the country’s largest DRAM producer, has made key progress on technology that raises DRAM storage density.

● Micron reported fiscal fourth-quarter revenue of $54.23 billion, with non-GAAP earnings of $33.42 per share.

● The board expanded the buyback authorization to $35.16 billion, the largest in company history, with expanded repurchases starting December 9.

Why was Micron Technology (NASDAQ:MU) the most actively traded US stock by dollar value on Monday? Shares of the memory chipmaker fell 3.88% to $989.04, and with roughly 23.7 million shares changing hands at a price near $1,000, about $23.45 billion worth of stock traded, according to market data. The trigger was a report that ChangXin Memory Technologies (CXMT), China’s largest DRAM producer, has made key progress on technology that raises DRAM storage density. CXMT reportedly also plans to launch a product aimed at the AI data center market later this year.

The headline landed on a nerve. Monday’s decline put Micron on track for a third straight daily loss, and the stock weighed on the broader semiconductor group. Shares traded between $978.50 and $1,002.67 during the session.

A Familiar Worry Returns

The selling replayed an anxiety investors have lived with since the summer. CXMT listed on Shanghai’s STAR Market on July 27, and its shares jumped about 466% on their first day of trading, according to market reports. Industry data cited in those reports showed CXMT held about 8% of the global DRAM market in the first quarter of 2026, ranking fourth worldwide. Fears about the durability of AI demand and the arrival of a well-funded Chinese competitor helped strip roughly 36% from Micron’s share price in the following weeks. Research published on October 7 projected that CXMT’s revenue will rise 506% in 2026 as AI demand lifts DRAM prices and volumes.

Monday’s report concerned a cell architecture known in the industry as “4F square.” SK Hynix and Samsung have announced similar progress, so the technology itself is not unique to CXMT. What unsettled investors is the prospect of another capable supplier competing in a market that Samsung, SK Hynix and Micron together have dominated with more than 90% share, according to industry data.

Not everyone sees the threat as imminent. Chris James, managing partner at investment firm Quadri, said CXMT “may be catching up, but it’s not there yet.” Press reports have indicated that CXMT’s technology trails the three incumbents by two or three generations, and that Apple (NASDAQ:AAPL), which had reportedly sought US approval to buy CXMT memory, reconsidered after the Chinese company asked for prices above those charged by SK Hynix and Samsung.

Monday’s turnover was heavy in dollar terms but not in share count: relative volume was 0.89, slightly below normal. Micron topped the list mainly because each share now costs close to $1,000.

What Micron Does

Boise, Idaho-based Micron makes DRAM and NAND flash memory, the chips that hold working data and long-term storage in everything from smartphones and PCs to AI servers. Its most strategically important product is high-bandwidth memory, or HBM, which sits beside AI accelerators and feeds them data. In its latest quarter, Micron reported revenue across business units including Core Data Center ($18.00 billion), Cloud Memory ($16.28 billion) and Mobile and Client ($13.11 billion). On its earnings call, management said it is working with Nvidia (NASDAQ:NVDA) on a custom HBM4E implementation for next-generation GPUs.

Latest Results and Guidance

The competition worry sits against financial results that would have seemed implausible two years ago. For the fiscal fourth quarter ended September 3, Micron reported revenue of $54.23 billion, up from $41.46 billion in the prior quarter and $11.32 billion a year earlier. GAAP gross margin reached 86.8% and non-GAAP earnings came to $33.42 per share. For fiscal 2026 as a whole, revenue was $133.19 billion versus $37.38 billion in fiscal 2025, and non-GAAP earnings were $75.52 per share. Average selling prices rose 180% for DRAM and 200% for NAND over the year.

Guidance points higher still. Micron forecast fiscal first-quarter 2027 revenue of about $61.5 billion, plus or minus $1.5 billion, non-GAAP EPS of $38.15, plus or minus $1, and gross margin of about 86.25%, which management called the low point for the fiscal year. Executives said supply and demand will be much tighter in fiscal 2027 and 2028 than in fiscal 2026. They also said Micron has locked in agreements covering the vast majority of its calendar 2027 HBM supply at significantly higher prices, and has signed 26 multiyear strategic customer agreements with take-or-pay commitments that it estimates cover more than 35% of revenue through 2030.

Capital returns are set to rise. Micron ended the quarter with $73.5 billion in cash and investments against $5.2 billion of debt, and plans to step up repurchases starting December 9. The board expanded the buyback authorization to $35.16 billion, the largest in company history.

Valuation

Micron trades at 13.33 times trailing earnings of $74.21 per share, with a market value of $1.12 trillion. The forward multiple is lower. A Wall Street estimate puts fiscal 2027 earnings at about $176 per share; at Monday’s close that works out to roughly 5.6 times, a discount that reflects deep skepticism about how long today’s pricing can last. Memory stocks have historically traded at low multiples near cyclical peaks, because investors expect earnings to fall when new supply arrives.

Bull Case vs. Bear Case

Bulls argue that this cycle is different. Take-or-pay contracts, customer deposits, which management said had grown to $32 billion, and HBM supply already sold out for 2027 make Micron’s earnings more visible than in past upturns. The 52-week range of $186.25 to $1,255.00 shows how far sentiment has traveled, and the stock remains up about 247% this year, with its rising 100-day moving average cited as potential support.

Bears focus on supply. Micron itself is raising capital spending, with about $25 billion planned for the first half of fiscal 2027, and new fabs in Idaho, Japan, Singapore and New York are due to come online between 2027 and 2030. Add a fast-growing Chinese competitor flush with IPO proceeds, and the risk is that today’s shortage eventually becomes tomorrow’s glut. Options traders appear split. Monday’s options flow leaned only narrowly bearish, at 50.4% of order flow, even as call volume over the past two weeks outpaced puts.

Micron’s Next Tests: CXMT Results and December Buybacks

The next datapoints arrive soon. CXMT is expected to report third-quarter results on October 31, which should show how quickly it is adding capacity and revenue. Details on its AI data center product will also matter. For Micron, the December 9 start of expanded buybacks and its fiscal first-quarter report will test whether guidance for record revenue and margins holds.