SoftBank Shares Plunge 10.72% After OpenAI Rules Out 2026 IPO

SoftBank Group shares tumbled 10.72% on September 14, closing at 5,795 yen in Tokyo, in their worst single-day sell-off since late June. The stock dropped more than 15% at one point during the session, making SoftBank the worst performer on the Nikkei 225, which fell 2% on the day.

The sell-off followed OpenAI CEO Sam Altman's confirmation that the company has no plans to go public in 2026. SoftBank has invested around $65 billion in OpenAI, and investors had expected an eventual IPO to provide a path to quick returns; the announcement pushes that timeline back.

Concerns were compounded by Anthropic CEO Dario Amodei's call over the weekend of September 12-13 for a slowdown in advanced AI development, supported by Elon Musk, Demis Hassabis and other leading AI developers. That contrasts with SoftBank founder Masayoshi Son's aggressive investment pace and added to worries about AI growth slowing.

SoftBank has taken on substantial debt to fund its OpenAI investment, including bridge loans secured by existing assets. The company announced during the week of September 7 that it planned to repay $25.9 billion of the $40 billion credit facility used to support its OpenAI investment, with repayment due by September 15. Bloomberg reported SoftBank also arranged a new two-year credit facility of $11.87 billion, with commitments from about 20 financial institutions. The company is also considering up to $20 billion in dollar bonds, $10 billion in financing backed by its OpenAI stake, and 1 trillion yen ($6.5 billion) in retail bonds.

SoftBank's AI exposure also includes chip design subsidiary Arm, whose valuation is tied to AI-driven semiconductor demand. The rout highlights investor sensitivity to AI spending prospects, OpenAI's future value and whether large-scale investments will pay off.