South Korea's KOSPI rose nearly 2 percent on Wednesday, lifted by strength in heavyweight semiconductor shares such as Samsung Electronics and SK Hynix. After sliding as far as the 6,700 level intraday, the index extended gains in the afternoon and finished trading around the 6,900 level.

The KOSPI closed up 133.31 points, or 1.95 percent, at 6,971.35. It opened down 23.55 points, or 0.34 percent, at 6,814.49.

The index fell to the 6,700 level early in the session before rebounding. It rose as high as 6,971.36 late in the session and effectively ended near its intraday peak, closing higher for the first time in four sessions.

In the main bourse, institutions net bought 334.3 billion won. Retail investors and foreigners net sold 1.43 trillion won and 548.5 billion won, respectively.

Among top market-cap stocks, semiconductor shares were strong. Samsung Electronics ended up 2.79 percent at 276,000 won, while SK Hynix rose 3.21 percent to 1,833,000 won.

Most other heavyweights also rose, including Samsung Electro-Mechanics, up 3.17 percent, SK Square, up 1.40 percent, LG Energy Solution, up 0.98 percent, Hyundai Motor, up 1.16 percent, Samsung Biologics, up 2.73 percent, and Samsung Life Insurance, up 0.71 percent. KB Financial Group fell 1.66 percent.

The KOSDAQ outpaced the KOSPI. The junior index ended up 38.38 points, or 4.48 percent, at 894.29.

In the Seoul foreign exchange market, the won was 0.50 won weaker at 1,358.50 per dollar as of 3:30 p.m.

Domestic stocks were seen as benefiting from easing supply-demand burdens as quarter-end global fund rebalancing ended, and from strong Micron results that lifted sentiment toward semiconductor investment.

Micron's fiscal 2026 third-quarter revenue and earnings per share topped market expectations, and its gross margin was 87.0 percent, beating the consensus estimate of 86 percent.

The company forecast that memory supply shortages in 2027 to 2028 would deepen compared with this year, and it also mentioned the possibility of expanding long-term supply contracts.

Concerns over rising long-term U.S. yields persist. The U.S. 10-year Treasury yield rose as high as the 5.3 percent range intraday the previous day. Still, the chance of an October Federal Open Market Committee rate hike fell after the August personal consumption expenditures price index came in below market expectations.

Han Ji-young (한지영), a researcher at Kiwoom Securities, said a rebound is expected on relief over the end of quarter-end rebalancing, the impact of Micron's earnings surprise, and expectations for South Korea's September exports.