Key facts
- KOSPI fell 2.99% at the opening bell on October 30, 2026.
- Google parent Alphabet shares dropped over 12% after missing revenue expectations.
- The Nasdaq Composite Index shed 1.38% and the Philadelphia Semiconductor Index fell 1.4% overnight.
South Korean stocks opened lower on Friday, October 30, 2026, mirroring losses on Wall Street amid renewed concerns about the sustainability of the artificial intelligence boom. The benchmark Korea Composite Stock Price Index (KOSPI) fell 2.99 percent to 5,760.35 at the opening bell. Overnight, Wall Street shares retreated, particularly technology stocks, as Google parent Alphabet's third-quarter revenue missed expectations despite a 25 percent year-on-year rise to $127.58 billion, raising worries about returns on significant AI investments. The tech-heavy Nasdaq Composite Index and the Philadelphia Semiconductor Index also declined, impacting sentiment towards South Korean chipmakers.