Seoul: South Korean stocks tumbled more than 4 percent Thursday due to losses in tech shares amid lingering concerns over profitability of artificial intelligence (AI) spending. The local currency rose against the U.S. dollar.

According to Yonhap News Agency, the benchmark Korea Composite Stock Price Index (KOSPI) fell 4.58 percent, or 301.88 points, to close at 6,296.38, after falling as low as 6,238.32. The index had previously risen 1.62 percent and 3.76 percent on Tuesday and Wednesday, respectively, driven by eased concerns over AI profitability.

After opening 1.81 percent lower, the KOSPI extended its losses, prompting the bourse operator to activate a sell-side sidecar for the KOSPI for five minutes at 10:18 a.m., halting program trading for KOSPI-listed shares.

Overnight on Wall Street, investors sold off Nasdaq-listed tech heavyweights, like Alphabet and Advanced Micro Devices, which pushed down the tech-savvy index by 0.83 percent due to doubts about the profitability of large-scale investment in AI infrastructure. However, signs of eased tensions in the Middle East pushed up the Dow Jones Industrial Average to rise 0.49 percent to a new record high.