Nikkei Drops 3.2% as AI Selloff and Bond Yields Hit Tokyo

Tokyo stocks experienced a sharp decline on August 19, with the Nikkei 225 closing at 65,326.42, marking a 3.2% drop and the lowest finish since August 4. The decline was primarily driven by renewed selling in artificial intelligence and semiconductor-related shares, coupled with rising bond yields, higher oil prices, and geopolitical concerns.

The selloff reversed much of the earlier recovery that pushed the Nikkei above 69,000. The broader market also weakened, but technology, semiconductor, optical-fiber, and data-center infrastructure names were hit the hardest. Investors had been optimistic about continued AI investment, but the August 19 session demonstrated the fragility of this confidence when bond yields rise and oil prices threaten inflation.

The decline followed weakness across Asian markets, particularly South Korea's Kospi, which dropped 5.7% due to sharp falls in Samsung Electronics and SK Hynix. This further pressured Tokyo's AI complex, as overseas investors often view Japanese semiconductor-equipment makers, South Korean memory producers, Taiwanese chipmakers, and U.S. AI shares as part of a connected technology trade.

Furukawa Electric saw a 14% drop, indicating that investors no longer view data-center infrastructure as a safe extension of the AI theme. Kioxia Holdings declined by 13%, highlighting the volatility and speculative positioning risks in the memory-chip sector. SoftBank Group fell 10%, significantly impacting the Nikkei due to its large index weighting and exposure to AI investment themes.

The market's cautious sentiment towards AI-related shares intensified, especially as higher bond yields reduced the present value of future growth and made investors less willing to pay high multiples for companies with long payback periods. Japanese government bonds reached a level not seen since 1996, with the 10-year yield nearing 3%, fueled by persistent inflation, fiscal concerns, and expectations for further Bank of Japan rate increases.

This rise in yields poses a significant risk for Tokyo equities, raising questions about the government's debt-servicing costs and the sustainability of large-scale spending plans. The Bank of Japan, under pressure to respond to the bond selloff, kept its policy rate at 1% but faced dissent from board member Hajime Takata for a potential increase to 1.25%.

The central bank remains vigilant, monitoring inflation, yen weakness, rising service prices, and wage growth to decide on further tightening measures.