Bloomberg data shows South Korea's KOSPI has posted a 63% year-to-date return volatility, above Bitcoin's 48%, making it the most volatile market among major national stock indexes tracked by Bloomberg. According to ChainCatcher, the elevated volatility stems largely from the index's heavy concentration, with Samsung Electronics and SK Hynix together accounting for more than 50% of KOSPI's weight.

The report also said retail-led leveraged ETF trading has amplified swings in the market. Related leveraged ETFs and the two chip stocks once accounted for more than 70% of daily turnover in the South Korean stock market. South Korean retail investors have bought more than 110 trillion won worth of KOSPI stocks this year, but their momentum-chasing and panic-selling behavior has further intensified volatility, turning the market into a highly leveraged trading venue centered on Samsung Electronics and SK Hynix.