KOSPI's Correlation with S&P500 Drops to 0.025 in July as Samsung, SK Hynix Dominate 52.3% of Market Cap

According to Herald Economy analysis, South Korea's KOSPI index has sharply decoupled from the U.S. S&P500 in July, with their monthly correlation coefficient falling to 0.025 from 0.5 in February, indicating a breakdown in synchronized movement. Samsung Electronics and SK Hynix now represent 52.30% of KOSPI's total market capitalization, transforming the index into a de facto semiconductor gauge.

The divergence is evident in recent volatility: KOSPI experienced 12 trading days with swings exceeding 5%, while S&P500 recorded none over the same period. This month, the Philadelphia Semiconductor Index and KOSPI have moved in lockstep, both declining 13.36% and 14.06% respectively, reinforcing that KOSPI increasingly mirrors semiconductor sector performance rather than broader U.S. equities.