Korean Chip Stocks Slide on China's DRAM Push, Raising Fears of Intensifying Competition

Construction continues at a semiconductor plant linked to Chinese memory chipmaker CXMT on the outskirts of Shanghai, China, on Aug. 4, 2026. (Yonhap) Shares of Samsung Electronics and SK hynix fell sharply on Oct. 13 as concerns mounted over technological advances by Chinese memory chipmaker ChangXin Memory Technologies (CXMT), raising questions about the competitive outlook for South Korea's semiconductor industry. As of 9:15 a.m., Samsung Electronics was trading at 238,500 won, or approximately $178.14, down 4.79% from the previous session, while SK hynix had declined 5.42% to 1,518,000 won. The selling followed an announcement by CXMT, China's largest DRAM manufacturer, outlining plans to introduce next-generation memory technology. At a recent conference in Shanghai, CXMT President Cao Kanyu said the company aimed to launch a server-grade DDR5 registered dual in-line memory module (RDIMM) incorporating a 4F² cell structure by the end of 2026. The announcement drew particular attention because Samsung Electronics is targeting mass production of its own 4F² DRAM technology in 2028. However, CXMT's proposed product launch and Samsung's mass-production target represent different development milestones and are not directly comparable. The 4F² architecture refers to a DRAM cell layout that occupies an area equivalent to four times the square of the minimum feature size, compared with six times that size in conventional 6F² designs. In principle, reducing the cell footprint by approximately 33% could allow manufacturers to increase memory density within the same chip area, although actual capacity, performance and manufacturing efficiency depend on the implementation. CXMT says its proprietary vertical surrounding gate (VSG) transistor technology addresses current leakage challenges associated with the new architecture. The company also claims to have secured more than 300 related patents. Its ambitions in server memory are drawing attention in South Korea, where Samsung Electronics and SK hynix are major suppliers of high-value-added DRAM products. CXMT, which has historically focused more heavily on consumer memory, is seeking to expand into a segment with demanding requirements for performance, reliability and customer qualification. The Chinese company's share of the global DRAM market reportedly reached 10% in the second quarter of 2026, compared with 4% a year earlier. South Korean analysts, however, caution that a technology announcement does not necessarily translate into competitive mass production. Han Ji-young, an analyst at Kiwoom Securities, said it was premature for the market to price in concerns about potential oversupply before CXMT had demonstrated the production yields, performance and customer qualification required for its next-generation products. Semiconductor industry officials similarly emphasized the distinction between developing a new cell architecture and manufacturing it consistently at commercial scale. CXMT's restricted access to advanced extreme ultraviolet (EUV) lithography equipment supplied by Dutch company ASML could also complicate its efforts to achieve competitive production yields. Nevertheless, the announcement has renewed attention on China's accelerating investment in domestic semiconductor research and development and its efforts to narrow the technological gap with established memory manufacturers. Semiconductor shares also weakened on Wall Street in the preceding U.S. trading session. Micron Technology fell 3.88%, while SK hynix's U.S.-traded depositary receipts declined 4.02%. Nvidia and AMD also came under selling pressure. The Philadelphia Semiconductor Index dropped 2.67%, reaching its lowest level in three weeks. Although the South Korean market may see attempts at a technical rebound following the recent declines, China's push for greater self-sufficiency in memory chips remains an important longer-term competitive factor. Samsung Electronics and SK hynix had each fallen by more than 4% in the previous session, extending their declines to four consecutive trading days.