South Korea’s Kospi index sinks more than 7% on semiconductor share sell-off over AI boom worries

Dealers walk past the screen showing the Korea Composite Stock Price Index (KOSPI) at a dealing room of Hana Bank in Seoul, South Korea, on Tuesday.Lee Jin-man / APShareAdd NBC News to GoogleOct. 13, 2026, 12:26 AM EDT / Source: The Associated PressBy The Associated PressHONG KONG — South Korea’s benchmark Kospi index dropped more than 7% Tuesday on a sell-off of chip shares, and Asian shares mostly declined after U.S. stocks ended mixed.

U.S. futures were also mixed, and oil prices fell as escalating tensions in the Middle East continued.

The Kospi index was down 7.4% to 5,914.35, its lowest level since late July. It reached an all-time high in June after crossing 9,000, supercharged by the global artificial intelligence boom.

Samsung Electronics fell 7.7%, while memory chipmaker SK Hynix plunged 8.8%.

Investors’ unease over the AI boom has clouded prospects. Both companies’ stocks fell following reports that the latest advances made by China’s memory chipmaker CXMT could increasingly challenge Samsung Electronics, SK Hynix and Micron Technology, the world’s biggest memory chipmakers.

Japan’s Nikkei 225 dropped 2.5% to 67,292.39. Chip equipment maker Tokyo Electron fell 6.6%. SoftBank Group, an OpenAI investor, lost 8%.

Hong Kong’s Hang Seng fell 1% to 24,033.51. The Shanghai Composite index was 1.1% lower at 3,754.82.

Australia’s S&P/ASX 200 edged down 0.2% to 8,767.40.

Taiwan’s Taiex fell 1.9%, with its leading chipmaker TSMC, or Taiwan Semiconductor Manufacturing Co., down 1.6%.

On Monday, Wall Street’s benchmark S&P 500 edged down 0.1%. The Dow Jones Industrial Average added 0.4%, and the technology-heavy Nasdaq composite declined 0.4%.

Investors are also watching this week’s earnings announcements by major firms including big banks, with Citigroup, JPMorgan Chase and Wells Fargo reporting results.

Oil prices dropped more than 1%. Brent crude, the international standard, fell 1.4% to $105.20 a barrel. That’s still higher than the roughly $72 per barrel in late February, before the Iran war.

Benchmark U.S. crude was down 1.5% to $92.34 a barrel.

“The market is more concerned over recent developments in the Middle East, with Houthi attacks on Saudi Arabia and the lingering risks to oil flows from the Persian Gulf,” wrote ING commodities strategists Warren Patterson and Ewa Manthey in a commentary Tuesday.

The U.S. dollar fell to 158.26 Japanese yen from 158.61 yen. The euro was trading at $1.1175, up from $1.1155.