What happened to the South Korean stock market? The volatile week has thrown the South Korean AI stock market into chaos.

The South Korean stock market rapidly turned from fervor to anxiety in just one week, exposing how fragile the AI market really is. The South Korean Kospi index briefly surpassed 9000 points on Monday, setting a new record high; the next day it plummeted by 10%, then regained most of the lost ground over the following two trading days; however, on Friday it experienced another large-scale sell-off, triggering a circuit breaker. Such extreme fluctuations indicate that the optimistic sentiment surrounding the global artificial intelligence investment boom is quickly giving way to doubts about whether this rally can be sustained. Since 2000, the South Korean stock market has only implemented circuit breakers 11 times, with two of them occurring this week alone. Investors have become unusually sensitive to AI-related news. Stocks of Samsung Electronics and SK Hynix both dropped by over 10% in Friday's trading session, as traders digested the two companies' massive capital investment plans while evaluating the impact of Apple raising product prices and reports of OpenAI potentially delaying its initial public offering. As foreign investors continue to sell off South Korean stocks, domestic retail investors are buying on the dip, with a net purchase of over $5 billion in Kospi stocks, slightly below the record purchase scale earlier in the week. This flow of funds further amplifies market volatility: a large number of retail investors relying on margin trading and the growing leverage ETF market will release larger buy and sell orders during market fluctuations.