SK Hynix Slumps Over 11% as HBM4 Equipment Delays, ChangXin DRAM Progress Spark Market Concerns

TradingKey - During the Asian trading session on October 15, the South Korean stock market dropped sharply. Intraday, the KOSPI Index's decline widened to 7%. As of press time, SK Hynix plummeted over 11%, and Samsung Electronics fell over 9%. The Korea Exchange triggered program trading curbs such as Sidecars, as market risk aversion heightened significantly.

[Source: TradingView]

An overnight decline in U.S. AI and semiconductor stocks was one of the external factors putting pressure on South Korean tech shares. After the U.S. September CPI came in higher than market expectations, interest rate markets raised bets on further rate hikes by the Federal Reserve. Rising interest rate expectations also increased valuation pressure on tech stocks with high valuations and capital expenditures.

According to South Korean media citing supply chain sources, some of SK Hynix's HBM4 back-end equipment originally scheduled for deployment in the second half of this year may be delayed until next year, with subsequent equipment order arrangements remaining unclear. The news sparked market concerns over the pace of HBM4 capacity expansion, though currently there is no evidence indicating substantial problems with the company's mass production schedule.

Meanwhile, ChangXin Memory Technologies (CXMT) disclosed R&D progress on 4F² DRAM and plans to introduce server DDR5 products. The market has begun evaluating the potential impact on traditional DRAM competition and pricing following future mass production, though CXMT's production scale, yield rates, and customer qualifications remain to be verified.

SK Hynix stated that AI infrastructure investment and HBM4 demand remain strong. Ahn Hyun, head of R&D at the company, stated on October 14 at the 2026 Semiconductor Exhibition in Seoul that growth in AI inference demand will drive the scale of AI infrastructure to expand by approximately 20 times by 2030.

SK Hynix's future performance will depend on HBM4 shipments, expansion progress, DRAM pricing, and AI capex, while also being affected by South Korean stock market trends, exchange rates, and global tech stock performance.

If equipment delays persist, the market may revise down short-term earnings expectations; if HBM demand and product prices remain strong, market concerns over earnings may be alleviated.