SoftBank Goes ‘All In’ on OpenAI With $41 Billion Bet

Masayoshi Son lifts SoftBank’s stake to 11% as AI infrastructure costs soar and competition around frontier models intensifies

SoftBank Group said on Wednesday that it has raised its stake in OpenAI to around 11% after completing the second stage of a $41 billion investment in the maker of ChatGPT, cementing one of the largest private financings in technology history.

The deal was executed in multiple tranches, combining capital from SoftBank’s Vision Fund vehicles with syndicated co-investments. It marks a decisive shift by SoftBank founder and chief executive Masayoshi Son, who is repositioning the group around artificial intelligence after years of volatile returns from earlier technology bets.

How the $41 billion deal was structured

SoftBank said the second tranche of $22.5 billion was completed this week, following an initial investment earlier this year after the group announced plans in April to invest up to $40 billion in OpenAI. The final figure exceeded that target slightly, reaching $41 billion.

According to the company, the funding breaks down as follows:

• $30 billion from SoftBank’s Vision Fund entities
• $11 billion from third-party co-investors through a syndicated structure

The scale of the transaction places it among the largest private capital raises ever seen in the tech sector, underscoring how expensive frontier AI development has become.

Son’s renewed AI conviction

Son framed the investment as a long-term, high-conviction bet on artificial general intelligence, or AGI.

“We are deeply aligned with OpenAI’s vision of ensuring AGI benefits all of humanity,” Son said in a statement.

AGI is widely seen as the next phase of AI, in which systems could outperform humans across a broad range of tasks. For Son, who has previously described AI as the defining force of the next economic era, OpenAI sits at the centre of that transition.

OpenAI’s need for capital keeps rising

OpenAI chief executive Sam Altman welcomed the expanded backing, saying it would allow the company to accelerate its roadmap.

“SoftBank saw the potential of AI early and committed with a deep belief in its impact on humanity,” Altman said, adding that SoftBank’s global scale would help OpenAI move faster.

The funding comes as OpenAI sharply increases spending on compute, talent and global infrastructure. Running and training large-scale models now requires unprecedented levels of capital, pushing even the most advanced AI companies to seek mega-round financing.

AI infrastructure becomes the real battleground

Beyond model development, SoftBank’s OpenAI investment ties directly into a broader infrastructure push. SoftBank and OpenAI, together with Oracle, are leading the Stargate initiative, a planned $500 billion effort to build next-generation AI data centre capacity in the United States.

The project reflects a growing industry view that control over compute, power and data centres may matter as much as model performance in determining long-term AI leadership.

A wider strategy beyond OpenAI

SoftBank’s AI focus is not limited to OpenAI. Earlier this week, the group announced a roughly $4 billion deal to acquire DigitalBridge, further expanding its exposure to data centres and digital infrastructure.

Taken together, the moves suggest SoftBank is building an AI-centric portfolio that spans models, platforms and the physical infrastructure required to run them—rather than betting on software alone.

Conclusion

SoftBank’s $41 billion investment in OpenAI highlights how the AI race has entered a new phase, defined less by experimentation and more by scale, capital and infrastructure. For OpenAI, the funding provides a deeper financial runway to compete at the frontier of AI development. For SoftBank, it represents a bold attempt to place itself at the centre of the global AI economy after years of uneven performance.

As competition intensifies among Big Tech firms and sovereign-backed investors, deals of this magnitude may become less of an exception—and more a signal of how expensive leadership in AI is set to become.

Quick Takeaways

• Stake increase confirmed: SoftBank Group has lifted its stake in OpenAI to about 11% after completing a $41 billion investment.
• One of tech’s biggest private deals: The transaction ranks among the largest private financings in technology, reflecting the rising capital demands of frontier AI development.
• Structured in stages: The funding includes $30 billion from SoftBank’s Vision Fund and $11 billion from syndicated co-investors, with the final $22.5 billion tranche completed this week.
• Masayoshi Son’s AI pivot: Founder Masayoshi Son is repositioning SoftBank around artificial intelligence after years of mixed returns from earlier investments.
• Fuel for OpenAI’s expansion: The capital will support OpenAI’s growing needs for compute, infrastructure and product development as it scales globally.
• Infrastructure is key: The deal aligns with large-scale AI infrastructure efforts, including the $500 billion Stargate project, highlighting how data centres and compute are becoming central to the AI race.