The KOSPI index experienced a 1.1% decline, closing at approximately 3,940 on Friday. This downturn reversed the gains from earlier sessions, spurred by a significant drop in semiconductor production that impacted major tech companies. South Korea's industrial output for October revealed a steep decline, with chip production falling by 26.5% compared to the previous month. This led to decreases in share prices for companies like Samsung Electronics and SK Hynix. Experts attributed this decline primarily to the strong base effect following a surge in September, despite sustained global demand fueled by the AI industry. The broader economic data contributed to a cautious market environment, with overall output decreasing by 2.5% and a sharp 14% reduction in facility investment, negatively affecting manufacturing and cyclical sectors. Companies such as Samsung Electronics (-1.8%), SK Hynix (-0.7%), LG Energy Solution (-5.7%), Doosan Enerbility (-0.8%), HD Hyundai Heavy Industries (-2.9%), and Hanwha Aerospace (-2.2%) all recorded losses. Furthermore, the absence of guidance from U.S. markets, due to the Thanksgiving holiday, left the index without additional external support.