South Korea’s manufacturing Composite Business Sentiment Index (CBSI), a gauge of corporate conditions, fell 4.3 points to 99.5 in September, its sharpest decline in four years. The drop followed five consecutive monthly increases through August, when the index reached 103.8, and pushed it below the 100 baseline for the first time since April. Strikes in the finished-vehicle sector, fewer working days during the Chuseok holiday and Middle East-related geopolitical risks weakened production and business conditions. Automobile production fell 22 points, while chemicals production dropped 12 points amid transport disruption, higher raw-material costs and petrochemical restructuring. Non-manufacturing sentiment improved 2.2 points to 98.9, supported by holiday food and beverage demand and increased outdoor activity. The Economic Sentiment Index (ESI), which combines business and consumer sentiment, rose 0.5 points to 99.9. October’s all-industry CBSI is forecast at 99.6, with manufacturing expected to weaken further while services and construction support non-manufacturing activity.