Memory chipmakers faced a rough session on Thursday, with shares of Micron Technology and South Korea's SK Hynix sliding even as broader U.S. indices advanced. The selloff was triggered by fresh data showing that China's ChangXin Memory Technologies (CXMT) has more than doubled its share of the global DRAM market over the past year, intensifying worries about competitive pressure from Chinese suppliers.
Micron fell as much as 2.3% before paring losses to about 0.8%, while SK Hynix dropped 4% and later recovered to a 2% decline. In contrast, the S&P 500 gained 0.4% and the Nasdaq rose roughly 0.8%, underscoring that the weakness was specific to memory names.
Market share shift rattles investors
According to a Counterpoint Research report, CXMT captured 10% of the global DRAM market in the second quarter of 2026, up from 4% a year earlier and 8% in the first quarter. The pace of share gains exceeded most analysts' expectations, prompting a reassessment of the competitive landscape.
The redistribution was stark. SK Hynix saw its DRAM share fall from 39% in Q2 2025 to 25% in Q2 2026. Samsung, meanwhile, increased its share from 33% to 38%, while Micron improved modestly from 22% to 24%. The overall DRAM market is expanding rapidly, with Counterpoint reporting sequential growth of 57% and year-over-year growth of 385%, driven by surging demand from AI data centers for both conventional DRAM and high-bandwidth memory (HBM).
HBM segment shows mixed picture
In the high-bandwidth memory segment, which is critical for AI applications, SK Hynix retained the lead with a 50% share, though that was down from 64% a year earlier. Samsung more than doubled its HBM share to 33%, and Counterpoint noted that Samsung is expected to gain further ground with the ramp of HBM4 shipments in the second half of the year. Micron's HBM share slipped to 18% from 21%, marking its first decline after holding steady for three quarters.
The selloff was amplified by a separate report from The Information, published earlier in the week, revealing that CXMT has begun producing advanced HBM in small quantities. The company plans to expand production in 2027, with Alibaba's T-Head semiconductor unit and Chinese AI chip designer Cambricon already testing CXMT's HBM. If testing succeeds, both companies could integrate CXMT's HBM into products as early as next year.
CXMT's rise and headline risk
CXMT's progress has been a recurring source of anxiety for memory investors. The company's blockbuster IPO raised 57.92 billion yuan (approximately $8.6 billion), making it Asia's largest IPO of the year and briefly valuing it at nearly $487 billion. Although CXMT remains behind the three established leaders in advanced memory technologies, its rapid share gains and entry into HBM have unsettled markets.
Recent reports that Apple was testing CXMT memory chips to address a memory shortage, and that Washington might allow Apple to source from Chinese suppliers, have added to the pressure. These headlines have repeatedly weighed on memory stocks, even though CXMT's revenue from advanced products remains minimal.
Analysts urge perspective
Not all analysts are convinced that the threat is as severe as headlines suggest. KC Rajkumar of Lynx Equity Research argued that supply constraints and qualification gaps limit CXMT's near-term impact. His channel checks found that CXMT is qualified for only one low-volume Mac product and not for iPhones, with poor yields on the high-density LPDDR5x DRAM Apple requires. "CXMT supply is unlikely to dent the shortage Apple is facing in DRAM, nor could CXMT supply improve Apple's negotiation position at traditional suppliers such as Micron," Rajkumar wrote.
Ellie Wang, an analyst at TrendForce, told CNBC that CXMT's capabilities remain limited in high-capacity server memory and advanced AI server products. This leaves Micron, Samsung, and SK Hynix with a substantial advantage in supplying the rapidly expanding AI infrastructure market, even as Chinese manufacturers continue to build capacity in conventional memory.
Long-term questions
Counterpoint Research Vice President Neil Shah highlighted the key variable: "An important thing to watch out for in H2 2026 would be how CXMT leverages its recent IPO to boost its prospects in terms of capacity expansion for HBM and LPDDR6." If CXMT can expand capacity and meet domestic and overseas demand, its market share could balloon, reshaping the competitive landscape within a year.
For now, investors are left to weigh the immediate headline risk against the longer-term fundamentals. The memory market remains robust, but the specter of Chinese competition is unlikely to fade. As seen in recent sessions, any sign of CXMT progress can trigger sharp moves in Micron and SK Hynix shares. Related coverage: Micron and SanDisk dip on China's memory ramp and Samsung and SK Hynix rebound on Dell's AI backlog.
This article is for informational purposes only and does not constitute financial advice.
