Seoul, May 6 - South Korea's benchmark KOSPI index surged above 7,000 points for the first time in history on Wednesday, fueled by an AI-driven rally in semiconductor stocks that catapulted Samsung Electronics into the $1 trillion market capitalization club.
The KOSPI rose as much as 5.8% to a record 7,338.61 in morning trading, driven by booming global demand for AI hardware.
Samsung Electronics and SK Hynix each jumped more than 10%, both hitting all-time highs. Samsung's rally lifted its market cap above $1 trillion, making it only the second Asian company after Taiwan Semiconductor Manufacturing Co to reach that milestone.
The rally triggered a rare "sidecar" trading curb after the market opened sharply higher, following an overnight surge in U.S. chip stocks that pushed the Philadelphia Semiconductor Index up 4.2%.
So far this year, the KOSPI has climbed 74%, after posting a 76% jump in 2025 - its best annual performance since 1999 - helped by government market reforms.
"Despite high oil prices and bond yields sparked by Iran war noises, foreign flow conditions are improving on a jump in the Philadelphia Semiconductor Index and AMD shares," said Han Ji-young, an analyst at Kiwoom Securities.
Shares of Advanced Micro Devices surged 12% in extended trading after forecasting second-quarter revenue above expectations, driven by demand for data-center chips as cloud companies accelerate AI infrastructure spending.
In currency markets, the won rose 1.2% to 1,458.9 per dollar, its strongest level since April 17.
Broader sentiment also improved after U.S. President Donald Trump said he would briefly pause an operation to escort ships through the Strait of Hormuz, citing progress toward an agreement with Iran, sending oil prices sharply lower.
Beyond tech, securities firms jumped 9.8% and financial groups rallied 4.1% on hopes a stock market boom would lift earnings. Foreigners were net buyers of local shares worth 1.2 trillion won.