South Korea's KOSPI Surges 165% Amid Extreme Volatility Driven by Samsung, SK Hynix, WSJ and FT Warn

According to Wall Street Journal and Financial Times reports on July 6, South Korea's stock market faces severe volatility warnings despite strong gains. The KOSPI index rose 165% over the past year, but experienced extreme daily swings; it moved 2% or more on 77 trading days in the period, compared to just 5 days for the S&P 500. Daily moves of 5% or more occurred 23 times for the KOSPI versus zero for the S&P 500.

Foreign investors are exiting the market rapidly, with net selling exceeding $100 billion in the first half of 2026 alone and $30 billion in June. WSJ noted leverage ETFs amplify volatility, and regulators including the Bank of Korea have expressed concern. The concentration risk remains acute: Samsung Electronics and SK Hynix now account for over half the KOSPI index, up from 36% at year start.