SoftBank shares slide 13% after AI chiefs sound alarm on safety

SoftBank Group Corp.’s shares slid the most in nearly three months after the heads of Anthropic PBC and OpenAI called on developers to tap the brakes on artificial intelligence development for safety reasons.

That’s heightened market jitters around the Japanese tech investor, which is taking on more debt to finance bets across the AI spectrum. SoftBank is one of OpenAI’s biggest backers, with total investment in the ChatGPT maker slated to reach close to $65 billion by October. Shares of SoftBank fell more than 13% Monday morning in Tokyo, their biggest decline since late June.

Investors are concerned about SoftBank founder Masayoshi Son’s faith in AI’s potential. He’s initiated a flurry of multibillion-dollar AI projects with uncertain timelines about payoff in revenue, dismissing talks about a possible bubble as “ignorant” and exposing his company to extreme volatility.


The company plans a ¥1 trillion ($6.5 billion) retail bond issue and a $10 billion loan linked to OpenAI shares as it finances deals such as the acquisitions of ABB Robotics and DigitalBridge. SoftBank’s also floated plans to build data centers around the world.

In recent days, Anthropic and OpenAI promised to rein in development of cutting-edge AI models following a series of disturbing security breaches. OpenAI co-founder Sam Altman also confirmed the startup will not list in 2026.

“There’s worry that OpenAI’s value may not be as high as previously expected,” said Yugo Tsuboi, chief strategist at Daiwa Securities. “The market is on alert because we do not yet know how much the pace of AI development will slow down.”

The leverage SoftBank’s taken on has weighed on its shares. Its stock price is down around 30% from a June peak, after Bloomberg News and other outlets reported OpenAI’s initial public offering could be delayed. They’ve also been hurt by concerns about heated competition in the AI sector and a raft of hacks and other unsanctioned activity.

Fears around AI’s investment prospects persist despite Anthropic chief Dario Amodei’s assurance that slowing the frontier development of AI capabilities won’t mean a slowdown in spending or growth. In the June quarter, SoftBank reported a profit, helped by big boosts from its stakes in Intel Corp. and TikTok developer ByteDance.