CXMT Corp., China's largest memory chipmaker, made a spectacular stock market debut, with shares surging nearly 466% and propelling it past Industrial and Commercial Bank of China to become the most valuable company listed on the mainland.
The company, which is the world's fourth-largest DRAM maker behind SK Hynix, Samsung, and Micron, priced its IPO at 8.66 yuan per share. Shares opened at 49.50 yuan and closed at 49 yuan, giving a market capitalization of about 3.3 trillion yuan ($487 billion). Trading volume exceeded 140 billion yuan, a single-day record for a mainland-listed stock.
The listing on Shanghai's STAR Market reignited debate over the impact of large IPOs on China's equity markets. The STAR 50 Index has slid almost 20% this quarter, and some analysts warned that CXMT's debut could pull cash from other technology stocks. The China Securities Regulatory Commission held meetings with market participants over concerns about fund diversion and issued a statement pledging to enhance market stability.
Only about 7% of CXMT's total shares were available for trading, with the remainder subject to lock-up restrictions. Analysts said the limited free float helped drive the massive first-day surge. The public tranche of the IPO drew 9.4 million individual orders totaling 7.07 trillion yuan, a subscription rate of 212 times the available allocation.
CXMT's IPO raised at least $8.6 billion, making it Asia's largest so far in 2025 and mainland China's biggest since Agricultural Bank of China's dual listing in 2010. Some sources reported the figure at $9.8 billion. Proceeds will be used to boost technological capabilities, primarily for memory wafer mass production and R&D projects.
The company is central to China's push for AI self-sufficiency, as advanced AI processors require massive amounts of high-speed memory, and a domestic supplier reduces dependence on foreign companies subject to U.S. export restrictions. CXMT has begun testing DRAM with Apple for devices sold in China, and major PC makers are exploring its products. However, its technology remains roughly one generation behind global leaders.
CXMT was founded in 2016 with an initial funding of 10 million yuan, backed by the Hefei city government. Hefei government-linked investors own 36.8% of CXMT, a stake worth 213 billion yuan at the IPO price — more than twice Hefei's annual revenue. The city's early bet epitomizes China's state-funded approach to building strategic industries. Founder Zhu Yiming, a Tsinghua graduate who studied and worked in the U.S., holds shares worth nearly 14 billion yuan.