SK hynix Inc. shares fell 4.23% in Seoul on Tuesday, putting them 31.1% below their Sept. 30 close despite the memory-chip maker’s strong second-quarter earnings.
The stock closed at 1,223,000 won, down 54,000 won from Monday. Historical price data from S&P Global Market Intelligence put its Sept. 30 close at 1,776,000 won.
South Korea’s KOSPI lost 215.27 points, or 3.73%, to close at 5,552.74, according to Korea Exchange figures. The index had fallen below 5,600 during Monday’s trading.
The wider selloff came amid concerns about returns on AI infrastructure investment.
The decline follows a longer retreat in chip stocks. By Oct. 16, SK hynix and Samsung Electronics shares were more than 50% below their June highs, even as contract quotes for two categories of PC memory had risen.
SK hynix reported revenue of 79.3187 trillion won and operating profit of 60.5426 trillion won for the second quarter of 2026. In its July 29 earnings release, the company linked its results to AI infrastructure demand. It said volume shipments of HBM4 high-bandwidth memory began during the quarter and that it had long-term agreements with about 10 customers.
The company said it planned to increase HBM4 production in the second half of 2026. In an Oct. 16 account of its OCP Global Summit 2026 presentation, SK hynix described memory technologies intended to help servers share data and handle AI workloads.
SK hynix’s next earnings release could provide another indication of customer demand after the October share-price decline. The company has not confirmed a date for that release.
