The Korean stock market experienced a significant downturn on Friday, with the KOSPI index dropping over 8% due to a sell-off in chip stocks. This decline erased the previous day's gains and triggered a market circuit breaker. Major chipmakers Samsung Electronics and SK Hynix saw their shares fall by approximately 9%. Foreign investors sold 2.5 trillion won ($16 billion) worth of KOSPI stocks during early trading. The sharp reversal followed Thursday's surge, which was driven by Micron Technology's optimistic earnings outlook and SK Hynix's plans to list in the U.S., boosting confidence in the sustainability of the AI investment boom. However, market sentiment deteriorated as investors reacted to news of Apple raising prices due to memory chip shortages and potential delays in OpenAI's IPO. Market analyst Fabien Yip noted that Apple's inability to absorb cost increases raises concerns about demand elasticity and chip profit margins, while OpenAI's IPO delay highlights tech stocks' vulnerability to retail investor sentiment shifts.