Chip Stocks Slide: SK Hynix Falls 10% or More and Samsung 7.4% After China’s CXMT Claims a Denser DRAM

REPORTED: The share and index moves below are intraday figures as CNBC and The Guardian reported them on 13 October 2026. They are not closing prices. CXMT’s product plan is the company’s own statement and has not been independently checked.

Shares in memory-chip makers fell sharply in Asia on Tuesday 13 October. CNBC reported that SK Hynix “plunged more than 10%” and Samsung Electronics “shed 7.4%”, with both at their lowest levels since August [1]. The Guardian put SK Hynix “down 10%” and Samsung down 7.4%, and said South Korea’s main stock index, the Kospi, “tumbled 6.25%” [2].

The two outlets’ SK Hynix figures differ slightly (“more than 10%” against “10%”), probably because they were taken at different times in the trading day.

How far did other markets fall? (REPORTED)

According to the Guardian [2]:

• Japan’s Nikkei fell 1.8% and the Taiwan exchange lost almost 2%, with TSMC down by a similar amount.
• Chip-equipment maker Tokyo Electron fell 7.15% (CNBC said 7.2%) and SoftBank Group lost 8.5%.

According to CNBC [1]:

• In Europe, ASML was down 3.3%, and STMicroelectronics and Infineon were both down 5% in early trade.
• Micron was down around 3.8% in US premarket trading, and SK Hynix’s US-listed shares around 5%.
• Shares in CXMT itself closed 2.8% lower in Shanghai.

What did the outlets say was behind it?

The two outlets give slightly different accounts. CNBC said the sell-off followed “worries over artificial intelligence financing and intensifying competition”, as investors weighed the progress claimed by China’s ChangXin Memory Technologies (CXMT) [1]. The Guardian linked the fall to CXMT’s announcement and to comments by Broadcom’s chief executive, Hock Tan [2].

TSN cannot say for certain what moved the market. These are the outlets’ explanations.

What CXMT said (company statement)

CXMT is China’s biggest maker of DRAM, the memory that computers and AI servers use for working data. Its president, Cao Kanyu, told a conference on Saturday 10 October that its first product using a “4F²” memory cell would be a server DDR5 RDIMM (a memory module for servers), due “by the end of the year”, according to remarks reported by Yicai and covered by Tom’s Hardware [3].

A 4F² cell stands the transistor on end, so each memory cell takes up about a third less space on paper than today’s designs. That means more memory in the same area of silicon. Samsung and SK Hynix have shown similar designs in research papers but have not yet sold them [3]. Cao said CXMT has more than 300 published patent families tied to 4F² [3].

Important caveats: CXMT gave no capacity, speed, die density, process node, named customers or planned volume. CXMT has not posted a release about the product in its Chinese or English newsrooms, and no one outside CXMT has tested it [3].

Analysts urge balance

Not everyone thinks the fall matches the threat. “Investors are jittery and looking for excuses to take profit on AI-related stocks that have outperformed this year, especially memory stocks,” Vey-Sern Ling of UBP told CNBC. He added that Chinese memory makers “continue to face technology hurdles, especially for more advanced memory like HBM” [1]. (HBM is the stacked, high-bandwidth memory used in AI chips.)

Phillip Wool of Rayliant Global Advisors said the reaction looked out of proportion. “More importantly, we’re not even talking about HBM here, and the Korean chipmakers are still unquestionably dominating that space,” he told CNBC. “I read that more as a sign of how vulnerable AI sentiment is at this moment” [1].

Context: Broadcom’s “casino” remark

The Guardian, citing Bloomberg, reported that Hock Tan told a conference in Singapore: “A lot of investors have no clue what they are investing in.” He said they “set very extreme expectations only to find out that it’s almost like they are in a casino” [2]. TSN covered that conference earlier: Broadcom and Intel bosses say money, not chips, may be AI’s biggest constraint.

What this means

• Memory stocks are jumpy. Big moves came on the same day as a product claim from a rival that has not yet shown a product.
• CXMT’s claim is untested. It is a date and a cell design, with no specs. The year-end deadline is about 11 weeks away.
• HBM is a separate market. Analysts quoted by CNBC say Korean firms still lead in the AI memory that matters most right now.

Sources

1. CNBC (Arjun Kharpal, Lee Ying Shan), tech stocks fall as SK Hynix, SoftBank and Samsung Electronics shares slide, 13 October 2026. https://www.cnbc.com/2026/10/13/sk-hynix-softbank-samsung-electronics-shares-tech-stocks-fall.html
2. The Guardian (Julia Kollewe), “Chip stocks slide after Broadcom boss likens AI investing to ‘casino'”, 13 October 2026. https://www.theguardian.com/business/2026/oct/13/chip-stocks-broadcom-ai-samsung-shares-cxmt
3. Tom’s Hardware, “CXMT president says company’s first 4F² DRAM will be a server DDR5 RDIMM, due by year-end”, 13 October 2026. https://www.tomshardware.com/pc-components/dram/cxmt-president-says-companys-first-4f2-dram-will-be-a-server-ddr5-rdimm-due-by-year-end-vertical-transistors-cut-each-memory-cells-footprint-by-a-third-on-paper-but-no-speeds-or-capacities-yet

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