SoftBank Group Corp. shares tumbled more than 11% on Monday to 5,795.0 yen, making the stock one of the weakest performers on the Nikkei 225, which dropped 2% during the session. The sell-off followed OpenAI CEO Sam Altman’s confirmation that the company will not pursue an initial public offering in 2026.
Altman told Fortune that an IPO would be “ill-advised” at this stage and that OpenAI feels no pressure to list before its business and governance are ready. Asked whether an offering had moved to 2027, he replied, “I would say not 2026,” but he did not confirm a 2027 timetable. OpenAI has not published a registration statement, selected an exchange, or disclosed a ticker or offering terms.
The announcement hit SoftBank particularly hard because the Japanese investment giant has committed nearly $65 billion to OpenAI and has already raised about $37 billion in 2026 to fund that position. SoftBank said last week that it expects to have invested nearly $65 billion by October. A public listing had been seen as a potential fast return on that bet.
SoftBank is financing the OpenAI stake with substantial debt. The company will repay $25.9 billion of an outstanding $40 billion loan by September 15 and has finalized a new $11.87 billion two-year loan from roughly 20 banks, exceeding an earlier $10 billion target. Bloomberg reported the company is also considering a U.S. dollar bond sale of up to $20 billion and a separate $10 billion margin loan backed by its OpenAI stake.
Pressure also came from the AI safety debate. Anthropic CEO Dario Amodei called for a slower pace of frontier AI development, and Altman said OpenAI supported the proposal. Elon Musk and Google DeepMind head Demis Hassabis backed the warning. For SoftBank, a broader AI slowdown could weigh on chip design subsidiary Arm, which has benefited from AI-driven semiconductor demand.
Despite Monday’s drop, SoftBank stock remains up nearly 26% in 2026. OpenAI’s structure still gives the nonprofit OpenAI Foundation control over OpenAI Group PBC through special voting and governance rights; the Foundation holds a 26% equity interest, while Microsoft owns roughly 27%.
