South Korean and Japanese stock markets experienced significant declines as a heavy sell-off in tech stocks unfolded, driven by a shift in global AI market sentiment and macroeconomic factors. In South Korea, Samsung Electronics and SK Hynix, which together represent about half of the KOSPI index's market cap, saw intraday drops of 7.4% and 10.1% respectively. This led to a more than 9% fall in the KOSPI index, triggering a 20-minute trading halt, the fourth such event this year. In Japan, the Nikkei 225 fell over 3% intraday, with major losses from SoftBank Group and chipmaker Kioxia, which declined by 10% and 14% respectively. Both indices had recently reached all-time highs, buoyed by optimism in AI advancements and geopolitical developments. However, the recent surge in tech stock prices has increased their susceptibility to market volatility, with analysts cautioning about elevated valuations and potential cyclical risks in the semiconductor sector.