CXMT 4F² DRAM progress knocks Samsung and SK Hynix shares
China's CXMT says it made progress on a smaller 4F² DRAM cell and plans DDR5 server memory by end-2026. Samsung fell 3.6% and SK Hynix 3.4% on October 12.
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China's ChangXin Memory Technologies (CXMT) says it has made "key progress" on a smaller type of DRAM memory cell. Shares of Samsung and SK Hynix fell on Monday, October 12, 2026, and Micron and SanDisk dropped later in US trading. CXMT plans server memory built on the new design by the end of 2026. If it can be made at scale, the design packs more memory into each chip, but analysts doubt that will be easy.
What CXMT announced
CXMT President Cao Kanyu spoke at an industry event in Shanghai over the weekend, according to Investing.com. TradingKey dates his remarks to October 10. The technical details come from the South China Morning Post, which several outlets cite.
DRAM is the working memory in computers and servers. Each chip holds billions of tiny cells. Mainstream DRAM uses a 6F² cell, while CXMT is working on a 4F² cell. The labels describe how much chip area each cell takes, so a 4F² cell is smaller. TradingKey says the move could cut the area of a single cell by about one-third in theory.
The design uses a transistor CXMT developed itself, called a Vertical Surrounding Gate. According to the reports, it reduces electrical leakage, the unwanted flow of current, and shrinks the space each cell needs.
Cao said a new generation of DDR5 RDIMMs for enterprise servers would arrive by the end of 2026. RDIMMs are the memory modules that servers use. CXMT "has not released detailed technical specifications or confirmed an exact product launch date," EconoTimes reports.
How memory stocks reacted
The reports give different figures because they captured prices at different points in the trading day.
| Company | Move reported | Reported by |
|---|---|---|
| Samsung Electronics | Down 3.6% to 252,500 won; down as much as about 4.2% during the day; down 4.4% | Investing.com, EconoTimes; TradingKey; TipRanks |
| SK Hynix | Down 3.4% to 1,624,000 won; down as much as about 4% during the day; down 4.5% | Investing.com, EconoTimes; TradingKey; TipRanks |
| CXMT | Down 3.1% to 49.42 yuan | Investing.com, EconoTimes |
| SanDisk | Down 7.12% in US trading | TradingKey |
| Micron | Down 4.70% in US trading | TradingKey |
TradingKey also says a DRAM-focused exchange-traded fund fell 4.61%. TipRanks says weakness in the wider market played a part in the drop.
The selloff comes at a strong time for memory makers. DRAM contract prices rose again in the third quarter as AI servers took capacity, and Samsung guided to record third-quarter profit last week.
Where Samsung and SK Hynix stand
Samsung and SK Hynix are also working on 4F² cells. SK Hynix set out a 4F² roadmap in 2025, according to Investing.com and EconoTimes. Samsung reportedly plans to mass-produce sub-10-nanometer DRAM based on the design by 2028.
CXMT is already a large supplier. Counterpoint figures cited by TradingKey rank it fourth in global DRAM revenue. TradingKey's two reports give its share as 7% and about 10%.
Why analysts are cautious
Morningstar analyst Jing Jie Yu says the structure cuts cell area by about 30%, TradingKey reports. But Morningstar's analysts also say bringing it to market could be "extremely difficult." The main problem is making the cells consistently in large volumes.
The benefit holds only if factory yields stay high, TradingKey adds. Yield is the share of chips that come out working. Higher process costs could also cancel out the gain in density.
What this means for developers
For teams that buy servers or plan memory-heavy systems:
- Nothing changes this year. CXMT has promised DDR5 server modules by the end of 2026 but has published no specifications. Do not plan capacity around them yet.
- Budget on today's prices. DRAM contract prices rose again in the third quarter. A denser design from a fourth supplier is worth watching, but analysts doubt quick mass production.
- Test before you trust new modules. Any new DDR5 RDIMM should pass your server maker's compatibility list and your own load tests before it goes into production.
- Watch three signals. CXMT's spec sheet, its first shipment dates, and any change to Samsung's 2028 target will show whether 4F² arrives early.
Sources
- Samsung, SK Hynix shares drop as China's CXMT flags progress in memory development - Investing.com
- Samsung, SK Hynix Face New Competition as CXMT Advances Memory Technology - TipRanks
- Memory Stocks Sold Off as SanDisk Tumbles 7%; CXMT Unveils Next-Gen DRAM Architecture, But Morningstar Says Commercialization Still Faces Major Hurdles - TradingKey
- Samsung, SK Hynix Shares Fall as China's CXMT Advances DRAM Technology - EconoTimes
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