The South Korean stock market closed sharply higher on Thursday, gaining over 5% and temporarily reclaiming the 9000-point level during the session. A broad-based rally in technology shares was fueled by better-than-expected earnings from U.S. chip giant Micron Technology.

The benchmark Korea Composite Stock Price Index (KOSPI) surged by 459.28 points, or 5.42%, finishing at 8930.30. It had briefly breached the 9000-point mark during trading, reaching an intraday high of 9044.04 points. This follows a 3.26% gain from the previous session.

The index opened significantly higher and triggered a temporary buying-side program trading suspension shortly after the market opened. The overnight release of a strong quarterly report from Micron Technology, the world's third-largest memory chip maker, helped alleviate market concerns about the sustainability of the artificial intelligence (AI) rally.

Companies such as Micron Technology, Samsung Electronics, and SK Hynix are all benefiting from the robust expansion in AI infrastructure, driven by growing market demand for memory chips and high-bandwidth memory (HBM).