SoftBank Doubles Down on OpenAI as AI Bets Swell to 60% of Portfolio

SoftBank has anchored itself to OpenAI’s trajectory, transforming the ChatGPT maker’s sharp rise into substantial unrealised gains and signalling its big appetite for artificial intelligence.

The Japanese investment conglomerate is intensifying its push into AI, committing tens of billions of dollars across semiconductors, digital infrastructure, robotics and foundational models as it positions itself for what it describes as the next phase of technological evolution.

AI-related holdings accounted for roughly 18% of SoftBank’s net asset value three years ago. They now represent more than 60%—a dramatic reweighting of the group’s portfolio towards a single transformative theme.

SoftBank’s most visible wager is its deepening relationship with OpenAI. The group has invested $34.6 billion in the AI developer, giving it an ownership stake of approximately 11%, following a $22.5 billion follow-on investment completed in December 2025.

The investment has already generated significant paper wealth. OpenAI’s valuation has climbed from about $150 billion in late 2024 to roughly $500 billion by October 2025. SoftBank is now reportedly preparing to invest a further $30 billion at a $850 billion valuation.

The group recorded a gain of about $14.6 billion in the fair value of its OpenAI stake in the previous quarter, followed by an additional $4.2 billion gain in the latest reporting period.

SoftBank’s AI strategy extends well beyond large language models. The company has adopted a vertically integrated investment philosophy, targeting the hardware, robotics and infrastructure it believes are essential to scaling AI.

It completed a $6.5 billion acquisition of chip designer Ampere Computing, and announced plans to acquire ABB Robotics’ business for about $5.4 billion, alongside a $3.1 billion deal for digital infrastructure investor DigitalBridge.

Executives have characterised these investments as foundational components required to support AI at scale. Rather than backing isolated startups, SoftBank sees itself as assembling the enabling infrastructure for an AI-led transformation.

The DigitalBridge acquisition also provides indirect exposure to data centre operator Switch and other hyperscale infrastructure assets, reinforcing SoftBank’s position across the AI supply chain.

Stargate and Infrastructure Expansion

SoftBank is also expanding aggressively into AI infrastructure through initiatives such as Stargate. The group recently partnered with OpenAI and its subsidiary SB Energy on the project, which includes developing a 1.2 gigawatt data centre in Texas and long-term infrastructure agreements to support the expansion of AI workloads.

Executives have dismissed suggestions that the rapid build-out of data centres signals an overheating market.

“There is media coverage or discussion that the data centre business is a bubble or part of the AI bubble… Hyperscalers are in great need of data centres… The current capacity is not sufficient to support growing AI computing,” said Yoshimitsu Goto, SoftBank’s Chief Financial Officer.

He acknowledged, however, that technological disruption remains a risk. “Technical innovation can be a risk… Perhaps new technologies may emerge that provide capacity without relying on data centres and electricity… Investment in physical assets carries such risk.”

For now, SoftBank remains confident that AI growth will demand ever-greater computing power.