Kospi jumps over 3% on gains in tech shares, renewed AI optimism

The Korea Exchange activated a buy-side sidecar on a busy day of trading that ended with the bourse at 5,638.34.

3% 오르며 반등한 코스피와 1,320원대의 환율 (서울=연합뉴스) 최재구 기자 = 27일 서울 중구 하나은행 본점 딜링룸에 코스피와 환율이 표시되고 있다. 이날 코스피는 전장보다 168.87포인트(3.09%) 오른 5,638.34로 원/달러 환율은 0.6원 오른 1,323.7원(15:30 기준가)으로 거래를 마쳤다. 2026.10.27 jjaeck9@yna.co.kr/2026-10-27 15:59:11/
A screen in Hana Bank's trading room in central Seoul shows the Kospi closing at 5,638.34 points on Oct. 27, up 168.87 points, or 3.09 percent, from the previous trading session.

Seoul shares closed higher Tuesday, led by gains in technology shares, as renewed optimism over AI and falling oil prices boosted risk appetite. The won weakened against the U.S. dollar.

The benchmark Kospi gained 168.87 points, or 3.09 percent, to close at 5,638.34.

As the market rallied on strong foreign buying, the Korea Exchange activated a buy-side sidecar at 10:13 a.m., suspending buy orders in program trading for Kospi-listed shares for five minutes. It was the first such action in four trading sessions.

The measure is triggered when Kospi 200 futures rise at least 5 percent and remain at that level for one minute or longer.

On Wall Street overnight, the Dow Jones Industrial Average gained 0.28 percent, while the S&P 500 advanced 0.7 percent and the tech-heavy Nasdaq Composite climbed 0.82 percent.

Investor sentiment improved after Anthropic disclosed strong revenue growth in its U.S. initial public offering filing, reigniting enthusiasm for AI-related stocks ahead of major tech earnings and the U.S. Federal Reserve's interest rate decision.

Oil prices fell on hopes of easing tensions in the Middle East, following reports of Qatari mediation efforts involving Iran and the United States.

Trade volume was light at 183.13 million shares worth 15.29 trillion won ($11.55 billion), with advancers outnumbering decliners 593 to 274.

Foreigners and institutions bought a net 592.97 billion won and 280.38 billion won, respectively, while individuals sold a net 947.78 billion won.

"Foreigners and institutions snapped up major semiconductor stocks amid renewed investment sentiment over AI, despite lingering macroeconomic concerns," Lee Kyoung-min, an analyst at Daishin Securities, said.

Market bellwether Samsung Electronics gained 4.23 percent to 222,000 won, and chip giant SK hynix increased 5.18 percent to 1.34 million won.

SK Square, the parent firm of SK hynix, jumped 7.67 percent to 828,000 won, and Samsung Electro-Mechanics, an electronics component affiliate of Samsung Electronics, surged 7.42 percent to 1.2 million won.

The local currency weakened by 0.6 won from the previous session to trade at 1,323.7 against the dollar as of 3:30 p.m. 

Bond prices, which move inversely to yields, closed higher. The yield on three-year Treasurys lost 3.1 basis points to 3.758, and the return on the benchmark five-year government bonds declined 3.3 basis points to 3.899.


Yonhap