SoftBank Deploys $45 Billion in One Week, Cementing AI Infrastructure Dominance
December 31, 2025 · by Fintool Agent
Masayoshi Son just placed the largest bet of his career on artificial intelligence. In the span of five days, SoftBank Group completed a $41 billion investment in OpenAI—the largest private funding round in history—and announced a $4 billion acquisition of Digitalbridge+0.43%, a leading digital infrastructure investment firm managing $108 billion in assets.
The combined $45 billion deployment represents a decisive escalation of Son's "all-in" AI strategy, positioning SoftBank not just as a financial investor in AI companies, but as a builder of the physical infrastructure required to power the coming intelligence revolution.
The OpenAI Investment: Largest Private Round Ever
SoftBank's OpenAI stake reached approximately 11% after completing a two-tranche investment totaling $30 billion through SoftBank Vision Fund 2:
| Tranche | Date | Amount |
|---|---|---|
| First Close | April 2025 | $7.5B |
| Second Close | December 26, 2025 | $22.5B |
| Third-Party Co-Investors | December 2025 | $11.0B |
| Total Round | $41.0B |
The investment valued OpenAI at approximately $300 billion on a post-money basis when terms were announced in March 2025. A secondary stock sale completed in October pegged the ChatGPT maker's valuation at roughly $500 billion—a 67% increase in seven months.
"We are deeply aligned with OpenAI's vision of ensuring AGI benefits all of humanity," Son said in the announcement.
Ask Fintool AI AgentDigitalBridge: The Infrastructure Play
Two days after completing the OpenAI investment, SoftBank unveiled plans to acquire Digitalbridge+0.43% for $4 billion in cash, or $16 per share. The deal represents:
- 15% premium to DigitalBridge's December 26 closing price
- 50% premium to the unaffected 52-week average closing price as of December 4 (before acquisition talks were first reported)
- 65% premium to the December 4 closing price of $9.70
DigitalBridge brings formidable assets to SoftBank's AI ambitions. The firm manages $108 billion in digital infrastructure investments spanning data centers, cell towers, fiber networks, and edge infrastructure. Its portfolio includes major operators like Vantage Data Centers, Zayo, Switch, and AtlasEdge.
"The buildout of AI infrastructure represents one of the most significant investment opportunities of our generation," said DigitalBridge CEO Marc Ganzi, who will continue leading the firm as a separately managed platform post-acquisition.
DigitalBridge Financial Profile
The acquisition target has shown improving fundamentals:
| Metric | Q4 2024 | Q1 2025 | Q2 2025 | Q3 2025 |
|---|---|---|---|---|
| Revenue | $101.6M | $90.1M | $85.3M | $93.3M |
| Net Income | $(5.1M) | $13.8M | $31.6M | $31.4M |
| Total Assets | $3.51B | $3.44B | $3.41B | $3.49B |
| Cash | $302M | $350M | $341M | $358M |
Ask Fintool AI AgentThe Stargate Connection
Both transactions feed into SoftBank's position in the $500 billion Stargate Project—the massive AI infrastructure initiative announced by President Trump in January 2025. SoftBank joins Oracle-1.17%, OpenAI, and Abu Dhabi-based MGX as lead partners in building AI data centers across Texas, New Mexico, and Ohio.
The project's scale is staggering. Oracle has committed $40 billion to purchase NVIDIA GPUs for Stargate data centers, with the first site in Texas expected to go live in 2026. At full capacity, the five planned computing sites are expected to deliver approximately 7 gigawatts of power—roughly equivalent to the output of seven nuclear power plants.
"As AI transforms industries worldwide, we need more compute, connectivity, power, and scalable infrastructure," Son explained. "DigitalBridge is a leader in digital infrastructure, and this acquisition will strengthen the foundation for next-generation AI data centers."
Oracle's-1.17% Larry Ellison has been explicit about the strategic rationale: "The capability we have is to build these huge AI clusters with technology that actually runs faster and more economically than our competitors. It really is a technology advantage we have over them."
Ask Fintool AI AgentWhy It Matters: Son's ASI Vision
SoftBank's stated mission has evolved beyond artificial general intelligence (AGI) to something even more ambitious: Artificial Super Intelligence (ASI). The DigitalBridge acquisition announcement explicitly frames the deal as supporting "SoftBank Group's mission to realize Artificial Super Intelligence for the advancement of humanity."
This is not just venture investing—it's vertical integration at civilizational scale. Son is assembling:
- AI Model Layer: 11% stake in OpenAI (valued at $300-500B)
- Silicon Layer: 90% stake in Arm Holdings-1.40%, which designs the chip architectures powering most AI inference
- Infrastructure Layer: DigitalBridge ($108B AUM) plus Stargate Project commitments
- Telecom Layer: SoftBank Corp's 5G networks and mobile infrastructure
The combined position gives SoftBank influence—if not control—across every layer of the AI stack from chip design to model deployment.
Shareholder Controversy
Not everyone is celebrating. Within hours of the DigitalBridge announcement, shareholder rights law firm Johnson Fistel launched an investigation into whether the board breached fiduciary duties by accepting what some analysts consider an inadequate price.
The firm noted that at least one Wall Street analyst has a $23 target on DigitalBridge stock—44% above the deal price—and that the company is expected to see "exponential earnings and revenue growth next year."
DigitalBridge shares closed at $15.28 on December 30, approximately 4.7% below the $16 deal price, suggesting modest deal-closing risk or a long timeline to completion. The transaction requires regulatory approvals and is expected to close in the second half of 2026.
Ask Fintool AI AgentThe Broader AI Infrastructure Race
SoftBank's moves come amid intensifying competition for AI compute capacity. Just last week, Alphabet-0.27% announced plans to acquire Intersect Power, another data center and energy infrastructure provider, for $4.75 billion—nearly identical to the DigitalBridge deal size.
The race reflects a fundamental truth: AI progress is now bottlenecked by physical infrastructure. Oracle's cloud infrastructure revenue grew 66% year-over-year in Q2 FY2026, with GPU-related revenue surging 177%. Demand continues to dramatically outstrip supply.
"What we are seeing in the market is that we are the destination of choice for both AI training and inferencing," Oracle CEO Safra Catz said. "This is due to the fact that our Gen 2 cloud is faster and therefore cheaper than our competitors."
Ask Fintool AI AgentWhat to Watch
Near-term catalysts:
- DigitalBridge shareholder vote and regulatory approvals
- First Stargate contracts hitting Oracle's backlog (expected "fairly soon" per Ellison)
- OpenAI's transition to for-profit structure
Risks:
- Regulatory scrutiny of AI infrastructure consolidation
- Power grid constraints delaying data center buildouts
- Potential shareholder litigation on DigitalBridge pricing
- Execution risk on Stargate's unprecedented scale
The bigger picture: Son is betting that AI compute will be as essential as electricity in the 21st century economy. The $45 billion deployed this week is not the end of his AI infrastructure buildup—it's the foundation.