KOSPI Slides Back Below 7,000 as Samsung and SK Hynix Drop

Samsung Electronics (005930.KS) and SK Hynix (000660.KS) shares fell 3.5% and 2.2% respectively on 11 September 2026 after reports that DeepSeek's AI models require less high-bandwidth memory (HBM). Investors are concerned about potential reduced demand for HBM, but experts note that the efficiency gains are specific to certain workloads and do not necessarily indicate a lasting change in global HBM demand.

SK Hynix and Samsung Electronics shares fell 2.2% and 3.5% respectively after DeepSeek reduced high-bandwidth memory requirements in its AI models, raising demand concerns. Despite cheap valuations and strong earnings, volatility persists. Investors see this as a short-term setback, with long-term demand expected to rise from other AI models.

Samsung Electronics and SK Hynix shares fell over 3% after DeepSeek unveiled its V4.1-Flash AI model, which significantly reduces memory requirements. The model uses 890 bytes of cache per token, a quarter of its predecessor's usage. DeepSeek's innovation could impact memory demand, affecting companies like Micron and SanDisk. DeepSeek is preparing for a Shanghai listing and recently raised funding at a high valuation.

Hedge fund Situational Awareness, which suffered massive losses in July, has resumed trading by spending hundreds of millions on call options for AMD, SanDisk, and other AI-related companies. According to Nomura, a large investor paid at least $315 million in premiums for options on these and other assets. The fund's founder, Leopold Aschenbrenner, previously achieved high returns with aggressive AI supply chain bets but faced a liquidity crisis in July.

Samsung Electronics and SK Hynix shares fell over 3% in Seoul after DeepSeek introduced an AI model using less high-bandwidth memory (HBM), raising concerns about future memory chip demand. Micron and SanDisk shares remained positive. DeepSeek's V4.1 Flash model reduces HBM and solid-state storage needs, potentially impacting memory industry growth. Samsung and SK Hynix shares are down over 25% from record highs.

Samsung Electronics and SK hynix shares fell 3.81% and 4.21% respectively, as U.S. tech stocks declined due to rising oil prices and Treasury yields. U.S. indices dropped, with the Nasdaq Composite down 0.65%. Nvidia and Micron also saw declines. Amotech surged 25.09% on earnings recovery expectations, while S2W rose 13.43% after joining an OpenAI-led cybersecurity initiative.