SoftBank ups OpenAI stake to 11% with $41B total investment and buys DigitalBridge for $4B
SoftBank increased its stake in OpenAI to about 11% after completing a $22.5bn second tranche, bringing its total investment to $41bn including $30bn from its Vision Fund and $11bn from co-investors. The group also agreed to acquire US data-center investor DigitalBridge for roughly $4bn, expanding its AI-related infrastructure holdings.
1. SoftBank Increases OpenAI Stake to 11% with $41 Billion Commitment
SoftBank Group announced that it has completed the second tranche of its investment in OpenAI, bringing its total funding to $41 billion and its ownership stake to approximately 11%. The Japanese conglomerate contributed $30 billion through its Vision Fund, while $11 billion was provided by third-party co-investors. This marks one of the largest private funding rounds in the technology sector and underscores SoftBank’s intensified focus on artificial intelligence under the leadership of founder Masayoshi Son.
2. Tranche Structure and Valuation Implications
The initial tranche of $18.5 billion closed earlier in the year, with the second tranche of $22.5 billion finalised this week. The deal originally valued OpenAI at roughly $300 billion post-money in April, according to internal projections, and subsequent secondary sales have suggested a valuation approaching $500 billion. SoftBank’s incremental capital injections have been structured as a combination of direct equity and syndicated co-investment, aimed at supporting OpenAI’s rapid scale-up of compute capacity and research facilities.
3. Strategic AI Projects and Collaborations
Beyond its equity position, SoftBank is co-leading the $500 billion Stargate initiative—alongside OpenAI and Oracle—to develop next-generation AI infrastructure in the United States. Announced in January 2025, Stargate encompasses the construction of high-performance data centres, customised AI hardware deployments and cloud-native orchestration layers designed to accelerate the transition towards artificial general intelligence (AGI). Masayoshi Son emphasised that SoftBank’s global network and capital firepower will enable OpenAI to advance core research milestones more rapidly.
4. Expanded Infrastructure Footprint with DigitalBridge Acquisition
In a complementary move to bolster its AI infrastructure capabilities, SoftBank entered into an agreement to acquire DigitalBridge, a US-based data-centre investor, for approximately $4 billion. The deal adds over 150 megawatts of critical power capacity across key North American markets and enhances SoftBank’s ability to support the large-scale compute demands of AI workloads. Analysts note that integrating DigitalBridge’s assets will reduce latency and drive down operational costs for SoftBank’s AI investments.