U.S. Inflation Climbs 0.6% in September as South Korean Stocks Slide

U.S. consumer prices rose in September as energy costs jumped, putting expectations for easing inflation under pressure and renewing focus on the Federal Reserve's interest-rate path.

The consumer price index rose 0.6% from August and 3.7% from a year earlier. Gasoline prices gained 9.1%, accounting for more than half of the monthly increase. Core CPI rose 0.3% for a second straight month and was 2.6% higher year over year, with housing, airfare and medical-service prices remaining firm.

The inflation figures sharpened attention on interest rates and risk assets. South Korea's KOSPI fell nearly 8% intraday, while Samsung Electronics and SK Hynix also declined amid reassessment of AI infrastructure returns and semiconductor valuations.

Attention now turns to whether inflation remains persistent and how the Federal Reserve responds to energy-driven price pressure.