China's biggest memory chipmaker jumps 472% in a $8.6 billion Shanghai IPO

CXMT, the Chinese maker of the dynamic random-access memory (DRAM) chips that go into phones, PCs, and AI servers, closed its Shanghai trading debut Monday up 472% at a market capitalization of roughly 3.3 trillion yuan (about $487 billion). The 8.66 yuan (around $1.20) listing price raised at least $8.6 billion, the second-largest initial public offering on a mainland Chinese exchange since Agricultural Bank of China's $22.1 billion listing in 2010, NBC News reported.

Under U.S. restrictions on advanced chipmaking equipment to China, CXMT, founded in Hefei in 2016, is the country's best-positioned producer of HBM: high-bandwidth memory, the stacked DRAM that feeds AI accelerators. CXMT grew its share of the global DRAM market from roughly 3% in early 2025 to about 8% in the first quarter of 2026, the fastest bit-output expansion of any major supplier, Counterpoint Research said in its Q1 2026 market note.

Trade-press reporting indicates CXMT delivered 16-nanometer HBM3 samples to Huawei in 2025 and is dedicating about 20% of its 2026 mass-production capacity to an HBM3 line, with HBM3E targeted for 2027 (Tom's Hardware, TechPowerUp). Samsung, SK Hynix, and Micron are pushing HBM4 into mass production in 2026, the same window. A sovereign HBM option does not erase the gap between the chip CXMT will be shipping next year and the chip its competitors will be shipping.

The scale gap is just as wide. CXMT's market cap, at roughly $487 billion, is now the largest of any company on a mainland Chinese exchange, CNBC reported. On revenue, the picture is different: CXMT's first-quarter 2026 sales of 50.8 billion yuan (about $7.5 billion), up more than 700% year on year, still leave the firm smaller than Samsung Electronics, SK Hynix, and Micron, each of which posted multi-billion-dollar quarterly profits in the same period on a much larger installed base. Counterpoint puts the Q1 2026 DRAM share of the top three at roughly 38% for Samsung, 29% for SK Hynix, and 25% for Micron.

DRAM and HBM prices have climbed through 2026 on AI demand, and the capacity additions Samsung, SK Hynix, and Micron have already announced are largely pre-sold. For Chinese hyperscalers and AI labs that cannot wait for offshore HBM allocations, CXMT is the only domestic supplier with the engineering base to ramp an HBM3 line, even on a node behind.

The second-order effect runs through Chinese AI infrastructure. HBM is one of the most expensive components in a modern AI accelerator, and a domestic supply lets Chinese model builders price AI training and inference against domestic memory cycles instead of imported HBM4 allocation. The Huawei customer relationship is the test case. The export-control regime that blocks Chinese buyers from Samsung's and SK Hynix's HBM4 lines makes the CXMT option a strategic asset, not just a financial one.

Two caveats belong in the price. First, the HBM3 ramp and the 20% capacity allocation are trade-press reports, not confirmed by CXMT filings, and a slip in yield or equipment deliveries would compress the option immediately. Second, even after a successful HBM3 ramp, CXMT still faces the same export-control ceiling on the extreme-ultraviolet (EUV) lithography tools and advanced packaging needed to make HBM4 competitive, the generation its customers will want by 2027.

The next concrete test is whether CXMT's third-quarter operating update confirms the HBM3 line is running at the planned 20% capacity, and whether a second Chinese customer outside Huawei publicly accepts the parts.