SoftBank shares plunge after OpenAI IPO delay triggers Nikkei slide

The Nikkei 225 closed 4 % lower, falling below the 70,000 mark, after reports that OpenAI is likely to postpone its initial public offering until at least next year. The news sent SoftBank Group shares tumbling more than 12 %, dragging down other AI‑related Japanese stocks such as Advantest, Tokyo Electron and Kioxia.

Analysts said the setback removed a key catalyst for the AI boom that has driven market optimism, while profit‑taking and higher crude‑oil futures added further pressure on equities. Despite the sharp decline, some market participants remain confident that AI and semiconductor sectors will resume their long‑term uptrend.

The broader market saw mixed moves, with Toyota, Mizuho and Sumitomo Mitsui banks edging higher, while overall trading volume remained elevated as investors reassessed exposure to AI‑related companies.