Key facts
- The KOSPI index gained 1.65% to close at 7,007.72 on Monday, September 21, 2026.
- Investor sentiment was buoyed by artificial intelligence and semiconductor stocks.
- Concerns over elevated crude oil prices and geopolitical risks in the Middle East persisted.
- Brent crude traded over $100 a barrel.
Seoul stocks rose 1.65% on Monday, September 21, 2026, extending gains for a third consecutive session. The benchmark Korea Composite Stock Price Index (KOSPI) closed at 7,007.72, driven by investor optimism in artificial intelligence and semiconductor shares. Despite the gains, persistent concerns over elevated crude oil prices, with Brent crude trading above $100 a barrel, and geopolitical risks in the Middle East weighed on sentiment. Meanwhile, in the US, major stock indexes opened higher, boosted by AI stocks, as Treasury yields retreated and crude prices tumbled more than 2%.