South Korean equities surged for a fourth consecutive session on Thursday, driven by aggressive foreign and institutional buying of major semiconductor stocks. The Korean won also strengthened against the US dollar.

The benchmark Korea Composite Stock Price Index (KOSPI) climbed 210.97 points, or 3.21 percent, to close at 6,790.01. The index had previously posted gains of 0.65 percent, 0.73 percent, and 3.68 percent over the prior three sessions. After opening 2.96 percent higher, the KOSPI extended its advance as foreign and institutional investors continued purchasing major chip heavyweights for the fourth straight day.

Trading volume was moderate, with 416 million shares valued at 34.45 trillion won ($24.22 billion) changing hands. Losers outnumbered gainers 532 to 332.

Foreign investors purchased a net 2.09 trillion won in stocks, while institutions bought a net 679.8 billion won. Retail investors, by contrast, offloaded a net 2.71 trillion won in shares.

Overnight in the United States, AI-related technology stocks advanced. The S&P 500 gained 0.26 percent, closing just short of a record high, while the Nasdaq Composite rose 0.54 percent. The Dow Jones Industrial Average, however, slipped 0.04 percent.

"Foreign buying remained strong, helped by relief that the US consumer price index for July came in line with expectations and a series of strong earnings reports from AI infrastructure companies," said Kang Jin-hyeok, an analyst at Shinhan Securities Co.

In Seoul, large-cap stocks broadly finished higher. Semiconductor leader Samsung Electronics surged 4.89 percent to 268,000 won per share, while rival SK hynix climbed 5.91 percent to 1.59 million won — both extending their winning streaks to three consecutive sessions. The two companies are the world's largest and second-largest memory chip makers, respectively, and their performance carries outsized weight for the KOSPI given that semiconductors are South Korea's largest export category. SK hynix is also a leading supplier of high-bandwidth memory (HBM), a critical component in AI accelerators, tying its fortunes closely to global data-center investment cycles.

SK Square, the parent company of SK hynix, jumped 9.08 percent to 1.12 million won. Samsung Electro-Mechanics, an electronics component affiliate of Samsung Electronics, soared 12.58 percent to 1.5 million won.

LG Energy Solution advanced 1.95 percent to 365,500 won, and Hyundai Motor, South Korea's largest automaker, gained 2.1 percent to 418,500 won.

The Korean won was quoted at 1,419.4 won against the US dollar at 3:30 p.m., up 3.7 won from the previous day's stock market close. (Yonhap)