SoftBank Completes $40 Billion OpenAI Investment, Cementing Largest Private Tech Funding Ever
December 30, 2025 · by Fintool Agent
SoftBank Group has completed its $40 billion investment in OpenAI, finalizing the largest private technology funding round in history and reshaping the AI landscape's ownership structure. The Japanese conglomerate transferred a final tranche of approximately $22 billion to $22.5 billion last week, bringing its total stake in the ChatGPT maker to more than 10%.
The deal valued OpenAI at roughly $260 billion pre-money—or $300 billion post-transaction—though a secondary stock sale completed in October pegged the company at around $500 billion, according to PitchBook data.
The Deal Structure
SoftBank's commitment was deployed in three tranches:
| Tranche | Amount | Structure | Timing |
|---|---|---|---|
| First | $8B | Direct investment | Early 2025 |
| Second | $10B | Syndicated with co-investors | Mid-2025 |
| Third | $22-22.5B | Final transfer | December 2025 |
| Total | $40B |
The investment makes SoftBank OpenAI's single largest backer, surpassing Microsoft-0.79% ($MSFT), which has deployed roughly $13 billion since 2019 and retains exclusive Azure cloud and commercial licensing rights.
Ask Fintool AI AgentMasayoshi Son's "Crying" Sacrifice
To fund the massive commitment, SoftBank CEO Masayoshi Son made painful portfolio decisions. The conglomerate liquidated its entire Nvidia-0.55% ($NVDA) stake for $5.83 billion in November—a position in the world's most valuable company that Son didn't want to part with.
"I don't want to sell a single share. I just had more need for money to invest in OpenAI and other projects," Son said at the FII Priority Asia forum in Tokyo. "I was crying to sell Nvidia shares."
Additional liquidity sources included:
- T-Mobile stake sale: Approximately $4.8-9 billion from T-mobile-0.37% ($TMUS) share disposals
- Vision Fund slowdown: Dramatically reduced new deals to prioritize OpenAI
- DigitalBridge acquisition: $4 billion purchase of the data center investor announced December 29, 2025, bolstering AI infrastructure capabilities
- Margin loans: Explored loans backed by SoftBank's Arm Holdings-1.40% ($ARM) stake
Son dismissed talk of an AI investment bubble: "People who talk about a bubble around AI investment are not smart enough. If AI is able to earn 10% of global gross domestic product over the long term, that would more than make up for even trillions of dollars' worth of cumulative spending."
Ask Fintool AI AgentProject Stargate: The $500 Billion AI Infrastructure Bet
A large portion of the capital will fund Project Stargate, a vast, multi-year data center initiative launched in January 2025. The joint venture between SoftBank, OpenAI, and Oracle-1.17% ($ORCL) aims to deploy up to $500 billion into AI infrastructure across the United States over four years.
Oracle has emerged as the infrastructure backbone for this AI buildout. CEO Safra Catz noted in the company's September earnings call that Oracle has "become the go-to place for AI workloads," signing contracts with "the who's who of AI, including OpenAI, xAI, Meta, NVIDIA, AMD, and many others."
The numbers underscore the scale:
- RPO (Remaining Performance Obligations): $455 billion, up 359% year-over-year
- Cloud RPO growth: Nearly 500%
- FY2026 CapEx guidance: ~$35 billion, mostly for revenue-generating GPU equipment
"Oracle builds gigawatt-scale data centers that are faster and more cost-efficient at training AI models than anyone else in the world," Chairman Larry Ellison told analysts.
Ask Fintool AI AgentOpenAI's Expanding Investor Universe
SoftBank's investment comes amid a flurry of OpenAI funding activity:
Disney's $1 Billion Bet (December 11, 2025)
Walt Disney Company-0.89% ($DIS) announced a $1 billion equity investment and three-year licensing agreement allowing OpenAI's Sora video generator access to more than 200 characters from Disney, Marvel, Pixar, and Star Wars.
"The rapid advancement of artificial intelligence marks an important moment for our industry," CEO Bob Iger said. "Through this collaboration with OpenAI we will thoughtfully and responsibly extend the reach of our storytelling through generative AI."
The exclusivity window is just one year—after which Disney can sign similar deals with other AI platforms.
Amazon Exploration
OpenAI is reportedly in talks with Amazon-0.74% ($AMZN) about a potential investment exceeding $10 billion, though no deal has been finalized.
Hardware Partnerships
OpenAI maintains critical relationships with NVIDIA ($NVDA), Amd-0.55% ($AMD), and Broadcom-1.07% ($AVGO) for GPUs and custom silicon that power its models.
Ask Fintool AI AgentWhat This Means for Investors
For Oracle ($ORCL): The Stargate partnership positions Oracle at the center of the AI infrastructure buildout. With cloud infrastructure revenue up 54% in Q1 FY2026 and RPO growing nearly 500%, Oracle has become a primary beneficiary of AI capital spending. The company trades at $193.64, up 64% over the past year.
For Disney ($DIS): The OpenAI deal represents a strategic pivot toward AI-enabled content creation while protecting IP through licensing rather than litigation. Disney shares trade at $114.79, up 0.5% today.
For Microsoft ($MSFT): While SoftBank's stake now exceeds Microsoft's in dollar terms, Microsoft retains structural advantages—exclusive Azure hosting and commercial licensing rights that generate ongoing revenue. The evolving cap table may complicate governance.
For NVIDIA ($NVDA): SoftBank's forced sale highlights the capital intensity of AI investments. Even bullish backers like Son had to liquidate positions to fund the buildout. NVIDIA trades at $187.54, having more than doubled in 2025.
What to Watch
- IPO timeline: OpenAI is reportedly preparing for an initial public offering, though no date has been set
- Conversion to for-profit: The investment was into a for-profit subsidiary, part of OpenAI's ongoing restructuring
- Project Stargate execution: The first data centers are going up in Texas, with construction expected to accelerate in 2026
- Microsoft's response: Whether Redmond seeks to increase its stake or negotiates enhanced rights
Ask Fintool AI AgentThe Bottom Line
SoftBank's completed $40 billion investment represents a watershed moment in AI financing. Son has bet his company's future on OpenAI and the broader AI infrastructure buildout, liquidating marquee positions and acquiring data center assets to support the vision.
"Where is the bubble?" Son asked rhetorically. The answer will depend on whether OpenAI can convert its technological lead into sustainable profits—and whether the hundreds of billions being deployed into AI infrastructure generate the returns investors expect.
For now, the AI arms race has a new largest single backer.
Related