China's ChangXin Memory Technologies triggered a global semiconductor sell-off Tuesday after announcing progress on a new chip architecture, sending Micron down 5%, SK Hynix down 10%, and Samsung down 7.4% while extending losses across Asian and European markets.
A weekend announcement from China's leading memory chipmaker set off a broad sell-off in global technology stocks Tuesday, wiping billions in market value from semiconductor companies across three continents.
ChangXin Memory Technologies, known as CXMT, said it had made significant progress developing a new chip architecture designed to increase memory density by packing more data into a smaller space. The announcement rattled investors already on edge about the durability of the artificial intelligence trade.
Micron Technology fell around 5% in U.S. premarket trading. SK Hynix's South Korean-listed shares plunged more than 10%, while Samsung Electronics shed 7.4% — both hitting their lowest levels since August. SanDisk dropped 5%, while Seagate and Western Digital each fell 7%.
The damage extended well beyond the United States and South Korea. In Europe, semiconductor equipment maker ASML declined 3.3%, and STMicroelectronics and German chipmaker Infineon both dropped 5%. Dutch firms BE Semiconductor and ASM International were each around 4% lower at the open.
In Japan, SoftBank Group — which holds a significant stake in OpenAI — sank 8.5%, leading a broader retreat in Japanese technology shares. Tokyo Electron dropped 7.2%, Advantest declined 2.9%, Lasertec fell over 5%, Disco lost 4.7%, and Renesas Electronics shed 5.9%.
CXMT itself closed 2.8% lower in Shanghai.
The sell-off follows a weak session on Wall Street, where the Nasdaq Composite dropped 0.44% on Monday. South Korea's Kospi fell 5.5% overnight.
CXMT is headquartered in Hefei and was founded in 2016. Until its initial public offering on Shanghai's STAR Market in July, it was little known outside China. The stock soared nearly 466% on its debut, briefly making it the most valuable China-listed company. Shares have since declined 4% from their IPO-day price of 49 yuan per share, though the company carries a market cap of 3.46 trillion Chinese yuan — approximately $520 billion — not far below tech giant Tencent's 3.87 trillion yuan valuation.
CXMT's global DRAM market share has risen to around 10%, up from roughly 4% a year ago, according to an HSBC note from Thursday.
The company reportedly plans to roll out a new server-memory product based on "4F square" cell architecture by the end of 2026. The design enables higher storage density, and SK Hynix presented its own roadmap for developing comparable technology in 2025.
Despite the market reaction, several analysts cautioned that the immediate competitive threat is more limited than the price moves suggest.
"Investors are jittery and looking for excuses to take profit on AI-related stocks that have outperformed this year, especially memory stocks," said Vey-Sern Ling, senior equity advisor at UBP. "In reality, while the Chinese memory makers can potentially become a threat to global demand-supply balance over time, in the short run they continue to face technology hurdles, especially for more advanced memory like HBM," Ling said.
Phillip Wool, chief market strategist at Rayliant Global Advisors, described the sell-off as disproportionate, noting that CXMT has yet to demonstrate large-scale production and continues to lag Samsung and SK Hynix in market share. "More importantly, we're not even talking about HBM here, and the Korean chipmakers are still unquestionably dominating that space, with very little threat at all from the likes of CXMT or anyone else for the foreseeable future," Wool said.
CXMT still faces meaningful constraints. U.S. export controls have effectively blocked the company from accessing ASML's extreme ultraviolet lithography machines, which are required to manufacture the most advanced semiconductors. Citi analysts noted in August that while U.S. government restrictions would prevent CXMT memory from entering American markets, sales to data centers in regions such as Europe could indirectly affect Micron.
Apple has been testing CXMT's DRAM chips for devices sold within China and was lobbying the U.S. government to permit broader use of the company's products, the Financial Times reported in July.
Wool warned that volatility could persist as investors reassess chip demand and how long semiconductor manufacturers can sustain their pricing power — a signal that the market's anxiety around the AI trade remains far from resolved.
Marc Sabatini is a staff writer at TechEchelon covering enterprise software, cybersecurity, and the regulatory beats that shape both. He focuses on the deal flow and policy decisions that move markets.
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