On 15 October 2026, the Nikkei fell ¥3,318.34 from the previous day to end trading at ¥64,425.95. Although it recorded the third-largest decline on record, selling in semiconductor-related and AI-related stocks was particularly notable among the main factors driving the fall.
On 15 October 2026, selling prevailed in technology stocks from the morning in the Nikkei Stock Average, and declines accelerated, particularly in stocks with large index contributions, amid turmoil in US AI-related stocks and renewed expectations of rate hikes by the Federal Reserve. The Nikkei fell ¥3,318.34 and ended trading at ¥64,425.95. This made it the third-largest decline on record.
Among Nikkei constituent stocks, 87 rose, 136 fell and 2 were unchanged. The largest negative contributors were Advantest, Tokyo Electron, SoftBank Group, Ibiden and Fujikura, weighing on the Nikkei. The largest positive contributors were Fast Retailing, Ryohin Keikaku, Chugai Pharmaceutical, Otsuka Holdings and KDDI.
Across the market, concerns about a slowdown in AI infrastructure investment came into focus, and selling intensified, particularly in semiconductor-related stocks. At one point, a single stock substantially dragged down the Nikkei. These developments spread downward pressure on the index across the broader market.