SoftBank Group Corp. shares slumped over 11% on Monday, trading at 5,795.0 yen, after OpenAI CEO Sam Altman announced the company will not seek a public listing (IPO) in 2026. The Nikkei 225 index also declined 2%.
SoftBank's shares have been strong year-to-date, up nearly 26% so far in 2026. The company has committed over $60 billion to OpenAI, using bridge loans secured by its other holdings to fund the investment.
Altman's comments came alongside Anthropic CEO Dario Amodei's call for a slowdown in broader artificial intelligence development due to potential risks to humanity. Other frontier model developers and figures, including SpaceX CEO Elon Musk and Google DeepMind head Demis Hassabis, supported Amodei's message.
The prospect of an OpenAI IPO would have provided SoftBank with strong, immediate returns on its investment, especially given the high valuations during the fundraises earlier in the year. The potential slowdown in AI development also threatens to negatively impact SoftBank's chip design subsidiary, Arm, and its broader tech holdings.
Arm's stock fell 8.5% on the news.
