Asian Markets on an AI High then Jolt as Powell Strikes Caution (Sept 23–24, 2025)

Asian equities extended their stunning September run on Sept 23, riding a wave of AI optimism and Wall Street’s record highs. Tech euphoria swept the region after Nvidia’s blockbuster plan to invest $100 billion in OpenAI, which turbocharged chip stocks globally business-standard.com business-standard.com. Momentum funds poured into Asian tech plays, fueling almost self-fulfilling gains. South Korea’s KOSPI, heavy with chipmakers, rose about 0.2% on Tuesday and was up nearly 9% for September business-standard.com business-standard.com. Taiwan’s TAIEX soared to an unprecedented peak, closing 1.4% higher at 26,247 points b2bnews.co.nz. Investors cheered advances in AI and data centers – Taiwan Semiconductor touched fresh highs, and peers like UMC and Compal Electronics hit limit-up on huge AI server orders focustaiwan.tw focustaiwan.tw. Even with Japan’s Tokyo market shut for a holiday, the region’s momentum was evident: MSCI’s Asia-Pacific ex-Japan index climbed ~0.3% to four-year highs, up ~5.5% this month business-standard.com business-standard.com.