Seoul:South Korean stocks experienced a significant surge of nearly 6 percent late Wednesday morning, driven by a rally in chipmakers after SK hynix reported record quarterly earnings and announced additional shareholder returns. The benchmark Korea Composite Stock Price Index (KOSPI) opened 2.23 percent higher and continued to rise, trading up 326.79 points, or 5.8 percent, to 5,965.13 as of 1120 a.m.

According to Yonhap News Agency, the Korea Exchange activated a buy-side sidecar shortly before 10 a.m., temporarily suspending buy orders in program trading for KOSPI-listed shares for five minutes. This measure is implemented when KOSPI 200 futures increase by at least 5 percent and maintain that level for one minute or longer.

The rally in South Korean stocks was also supported by gains in U.S. markets overnight, particularly in artificial intelligence-related technology shares. The Nasdaq Composite rose by 1.18 percent, and the Philadelphia Semiconductor Index increased by 3.6 percent, enhancing investor sentiment towards South Korean chipmakers.

Earlier in the day, SK hynix announced record-high revenue and operating profit for the third quarter due to strong demand for memory chips. The company also revealed a shareholder return program valued at over 100 trillion won (approximately US$75.3 billion) for 2026. Despite this positive market movement, investors remained cautious ahead of the Federal Reserve's upcoming rate decision, seeking indications of future U.S. interest rate paths.

Major KOSPI stocks saw significant increases, with Samsung Electronics rising 7.77 percent and SK hynix gaining 7.76 percent. SK Square, the parent company of SK hynix, surged by 8.7 percent, while Samsung Electro-Mechanics, an affiliate of Samsung Electronics, jumped 9.16 percent. At 1120 a.m., the Korean won was trading at 1,336.0 won against the U.S. dollar, a decrease of 9 won from the previous session's close.