SoftBank has completed the final $10 billion tranche of its planned $30 billion follow-on investment in OpenAI. This closes one of the largest AI investments announced this year.
The Japanese technology conglomerate completed the transaction on October 1 through SoftBank Vision Fund 2. With the latest investment, SoftBank said its cumulative investment in OpenAI has reached $64.6 billion. As a result, it now has an ownership interest of approximately 13%.
The investment arrives as OpenAI continues to raise enormous amounts of capital to expand computing infrastructure. In addition, it develops AI models and supports growing demand for its products.
SoftBank Completes the Final $10 Billion Investment
The latest transaction represents the third and final part of SoftBank’s $30 billion commitment to OpenAI. Rather than transferring the entire amount at once, SoftBank structured the investment across three $10 billion tranches scheduled throughout 2026.
The first tranche closed on April 1, followed by the second on July 1. The final $10 billion was completed on October 1, bringing the entire follow-on investment to a close. SoftBank made the investments through SoftBank Vision Fund 2.
The securities acquired through the investment are preferred shares. They are designed to automatically convert into common shares if OpenAI completes an IPO or a related listing transaction.
SoftBank’s Total OpenAI Investment Reaches $64.6 Billion
The new investment pushes SoftBank’s total capital invested in OpenAI to $64.6 billion. This highlights how deeply the Japanese group has committed itself to the AI company.
SoftBank had already invested $34.6 billion in OpenAI since September 2024 through Vision Fund 2. The additional $30 billion commitment announced in February brought the expected cumulative investment to $64.6 billion. That figure is now reflected in SoftBank’s completed transaction.
SoftBank said its resulting ownership interest in OpenAI is approximately 13%. The investment gives the Japanese conglomerate significant financial exposure to the future growth of one of the world’s most closely watched AI companies.
OpenAI’s $110 Billion Funding Round
SoftBank’s investment is part of a much larger financing effort by OpenAI. In February, OpenAI announced $110 billion in new investment at a $730 billion pre-money valuation. SoftBank contributed $30 billion, NVIDIA contributed $30 billion and Amazon committed $50 billion.
The funding was announced alongside major infrastructure partnerships. OpenAI said the additional capital would help it secure the computing capacity, distribution and financial resources needed to meet growing demand from consumers, developers and businesses.
The scale of the financing says plenty about the economics of frontier AI. Building increasingly capable models is no longer simply a research expense. Companies also need access to enormous amounts of computing infrastructure to train models and run them for users.
Computing Power Is Becoming a Core AI Investment
OpenAI’s financing strategy is closely tied to its need for more computing capacity. The company has been expanding its relationships with major infrastructure providers as demand for AI models continues to increase.
OpenAI said its February agreement with NVIDIA would provide next-generation inference compute. Meanwhile, its strategic partnership with Amazon includes access to large amounts of AWS infrastructure. Amazon also agreed to invest $50 billion in OpenAI.
The infrastructure requirements are substantial. OpenAI and Amazon said OpenAI would consume 2 gigawatts of Trainium capacity through AWS infrastructure to support workloads including OpenAI’s Stateful Runtime Environment, Frontier and other advanced systems.
That puts infrastructure spending at the centre of the AI investment story. The companies building frontier models need not only researchers and software, but also chips, data centres, networking capacity and electricity.
SoftBank Used Debt Financing for the Final Tranche
SoftBank also disclosed how it funded the final $10 billion investment. The company said the third tranche was financed using proceeds from the issuance of foreign-currency-denominated senior notes announced on September 24.
The financing comes after SoftBank had arranged a much larger bridge facility earlier in the year to support its OpenAI investment. The company initially established a $40 billion bridge facility, with $30 billion eventually drawn.
SoftBank later repaid the outstanding bridge borrowings early. On September 30, it also canceled the remaining $10 billion of undrawn capacity. This means there are now no remaining borrowings or undrawn commitments under that facility.
OpenAI Needs Capital at an Unusual Scale
OpenAI’s capital requirements reflect the changing economics of advanced AI. The company is operating large consumer and enterprise products. At the same time, it is investing in model research and the infrastructure required to serve those systems at scale.
Its February financing announcement explicitly framed compute, distribution and capital as the three requirements needed to meet rising AI demand. The $110 billion investment package was designed around those needs. At the same time, the company also announced strategic relationships with Amazon and NVIDIA.
That makes SoftBank’s $30 billion investment more than a conventional technology investment. It is capital flowing into a company whose expansion depends heavily on physical computing infrastructure. In addition, long-term access to enormous amounts of processing capacity is essential.
SoftBank’s AI Strategy Gets an Even Bigger OpenAI Position
For SoftBank, the completion of the investment significantly increases its exposure to OpenAI. This places the company at the centre of its broader artificial intelligence strategy.
SoftBank said in February that its additional investment was intended to support OpenAI’s continued growth. The company has already invested $34.6 billion since September 2024. Therefore, its latest commitment brings its cumulative OpenAI investment to $64.6 billion.
The October transaction now closes that $30 billion commitment.
What happens next will depend on OpenAI’s ability to translate the capital into additional computing capacity, products and commercial growth. For SoftBank, the size of the position means OpenAI’s development has become a major part of its wider AI investment strategy.
The Bigger AI Financing Story
The SoftBank transaction is another indication of how quickly the financial requirements of frontier AI are expanding. Investments that once looked extraordinary in the technology sector are becoming part of the infrastructure race surrounding advanced models.
OpenAI’s $110 billion financing announcement, SoftBank’s $64.6 billion cumulative investment and the company’s expanding infrastructure agreements with Amazon and NVIDIA all point toward the same underlying trend. AI development increasingly requires access to capital on a scale normally associated with major infrastructure projects.
SoftBank has now finished its part of the deal.
The much bigger question is what OpenAI builds with the money.
Sources
- Reuters — SoftBank completes final phase of $30 billion investment in OpenAI
Read the Reuters report - SoftBank Group — Execution of Follow-on Investment (Third Tranche) in OpenAI
- OpenAI — Scaling AI for everyone

