South Korea's KOSPI jumped nearly 5 percent, led by heavyweight semiconductor shares, triggering a buy sidecar on the main board. The KOSDAQ also climbed more than 6 percent to regain the 840 level.

As of 12:57 p.m. on Thursday, the KOSPI was up 351.13 points, or 4.82 percent, at 7,643.04 from the previous session's close. It opened up 260.58 points, or 3.57 percent, at 7,552.49.

The Korea Exchange activated a buy sidecar on the main board at 12:54:55 p.m. As a result, the validity of program-trading buy orders was suspended for 5 minutes.

Institutions were net buyers of 1.7276 trillion won, leading the rise on the main board. Retail investors and foreigners were net sellers of 1.3716 trillion won and 287.6 billion won, respectively.

Top market-cap shares rose across the board. Samsung Electronics was up 17,500 won, or 6.29 percent, at 295,500 won. SK Hynix gained 56,500 won, or 2.58 percent, to 2,242,500 won.

SK Square rose 5.95 percent, Samsung Electro-Mechanics gained 7.30 percent and Hyundai Motor added 4.38 percent. LG Energy Solution rose 3.83 percent, Samsung Life gained 4.91 percent and Samsung Biologics advanced 6.19 percent. KB Financial surged 9.80 percent.

The KOSDAQ also rose sharply. At the same time, it was up 48.74 points, or 6.14 percent, at 842.74 from the previous session's close.

The won was at 1,509.40 per dollar, down 2.40 won, or 0.16 percent, from the previous session.

The rebound in semiconductor stocks on Wall Street overnight, as expectations for AI investment recovered, is seen as influencing domestic investor sentiment. Micron, Broadcom and AMD showed strength, and the Philadelphia Semiconductor Index also rose.

The planned listing of SK Hynix ADRs on the U.S. stock market is also cited as a factor stimulating investor sentiment toward semiconductor shares. The market is watching the ADR price that will form in the U.S. market and whether it trades at a premium to the domestic shares.

Han Ji-young (한지영), a researcher at Kiwoom Securities, said the domestic stock market is expected to show strength on the back of positive news from the United States, gains in KOSPI 200 night futures and inflows of bargain buying after a midweek adjustment. He also said strong demand for the SK Hynix ADR listing could improve investor sentiment across the KOSPI, including semiconductors.