The Nikkei Stock Average fell more than 1,200 points on Monday, September 14, briefly dropping below 63,000 for the first time since August 4. Selling centered on AI and semiconductor stocks after Anthropic CEO Dario Amodei urged the industry to slow development and OpenAI CEO Sam Altman indicated he was considering a similar move. Investors feared slower AI progress could reduce demand for data-center memory and limit semiconductor manufacturers' capital spending. SoftBank Group, an OpenAI investor, fell more than 10% at one point after Fortune reported that Altman said OpenAI would not pursue an initial public offering (first sale of shares to public investors) in 2026. Middle East tensions and oil prices near $103 a barrel added pressure. South Korean chipmakers also declined sharply, while investors are now watching major companies' capital spending plans and AI development strategies.