SoftBank

SoftBank Group Corp. is a strategic investment holding company whose AI activities include financing OpenAI, partnering on U.S. computing infrastructure and developing an enterprise-AI offering with OpenAI. Its organization combines subsidiaries such as Arm, direct investments and fund portfolio companies. SoftBank Corp., a separate group company, contributes enterprise implementation and develops AI applications for telecommunications infrastructure.[10][4][8][9][13]

On February 27, 2026, SoftBank Group entered a definitive agreement to invest another $30 billion in OpenAI Group PBC through SoftBank Vision Fund 2, at a $730 billion pre-money valuation. It had already invested $34.6 billion through that fund since September 2024. The agreement was subject to customary closing conditions; upon full completion, SoftBank expected cumulative investment of $64.6 billion and approximately 13% ownership.[4]

Chairman and CEO Masayoshi Son connected the investment to SoftBank’s artificial superintelligence ambitions: “Through this additional investment, we will accelerate OpenAI’s research and ecosystem expansion, while advancing our own ASI strategy.”[4]

SoftBank executed a $10 billion first tranche on April 1 and a $10 billion second tranche on July 1, 2026, totaling $20 billion under the new commitment. It borrowed $10 billion under its March 27 bridge facility on each investment date to fund the respective installment. The July announcement scheduled the final $10 billion for October 1, Japan time, with possible acceleration if OpenAI shares were publicly listed.[5][6]

The financing plan initially called for bridge loans and other arrangements, expected to be replaced over time through existing assets and other financing measures. On September 9, 2026, SoftBank announced that it had notified lenders of its decision to prepay the entire $25.9 billion outstanding bridge balance on September 15. At that announcement, the facility’s capacity was $40 billion and aggregate borrowings drawn were $30 billion.[4][7]

The 2026 investment followed two partnerships announced in early 2025. In January, SoftBank and OpenAI announced Stargate, a new company intended to invest $500 billion over four years in U.S. AI infrastructure for OpenAI, beginning with a planned immediate deployment of $100 billion. SoftBank took financial responsibility and OpenAI operational responsibility; the initial equity funders were SoftBank, OpenAI, Oracle and MGX. Masayoshi Son was named as the future chairman.[8]

Stargate’s initial technology partners were Arm, Microsoft, NVIDIA, Oracle and OpenAI. Oracle, NVIDIA and OpenAI were assigned the collaboration to build and operate the computing system. At the announcement, buildout was underway in Texas, while additional sites were being evaluated and definitive agreements finalized.[8]

In February 2025, OpenAI and SoftBank Group announced Cristal intelligence, an enterprise-AI offering designed to integrate each company’s systems and data. The proposed agents would handle tasks such as generating financial reports, drafting documents and managing customer inquiries. SoftBank Group announced $3 billion in annual spending to deploy OpenAI solutions across group companies, including Cristal intelligence and ChatGPT Enterprise. SoftBank Corp. separately set a goal of automating over 100 million workflows.[9]

The partners agreed to establish SB OpenAI Japan to market Cristal intelligence exclusively to major companies in Japan. The announced ownership was 50:50 between OpenAI and a company established by SoftBank Group Corp. and SoftBank Corp., with the venture consolidated to SoftBank Corp. OpenAI would provide research, technology and engineering support; SoftBank Corp. would second sales staff and engineers; Arm would supply supporting compute technology.[9]

The implementation plan included additional training and fine-tuning in secure environments, with agents integrated into customers’ IT systems. The partnership excluded confidential or personal information used in communications from training data and proposed exploring storage of customer data on servers in Japan-based AI data centers.[9]

SoftBank also expanded its semiconductor ownership during 2025. On November 25, U.S. time, it completed the acquisition of all equity interests in Ampere Computing through Silver Bands 6 (US) Corp., making Ampere wholly owned. Ampere designs semiconductors for high-performance, energy-efficient AI computing based on the Arm compute platform.[12]

Before the OpenAI enterprise partnership, SoftBank Corp. was developing AI applications on telecommunications infrastructure. In November 2024, it installed NVIDIA AI Enterprise on AITRAS edge servers. AITRAS was an under-development solution designed to run AI and radio access network workloads on the same infrastructure. NVIDIA supplied NeMo for building and customizing foundation models and NIM inference microservices.[13]

• Robot control: SoftBank Corp. developed an edge-hosted LLM that generated robot motions from sensor information. AITRAS exchanged sensor input and model-generated control output with the robot, allowing the model to use external computing resources rather than rely on the robot’s onboard capacity.[13]
• RAG Menu @Edge: Enterprise retrieval-augmented generation applications searched corporate information to inform LLM responses. Data processing stayed on AITRAS edge servers in a closed environment, which SoftBank Corp. positioned as more secure than using cloud services over the internet.[13]
• Traffic Understanding Multimodal AI: A model trained on traffic knowledge, Japanese traffic regulations, risk scenarios and countermeasures analyzed conditions and generated vehicle instructions for remote autonomous-driving support.[13]

SoftBank’s operating businesses and investment structure predate these AI projects. Masayoshi Son founded SOFTBANK Japan in 1981. Its business focus moved from PC software to the internet, broadband and smartphones. The 2026 company history describes Son’s original conception as a “software bank” supplying infrastructure for an information-driven society.[10]

The Vision Fund’s first major closing, announced on May 22, 2017, brought over $93 billion in committed capital. Investors included SoftBank Group, Saudi Arabia’s Public Investment Fund, Mubadala, Apple, Foxconn, Qualcomm and Sharp or their affiliates. SoftBank’s commitment was capped at $28 billion, including expected in-kind contributions. The fund’s planned sectors included AI and robotics alongside communications, cloud software, computational biology and other technologies.[11]

SoftBank controlled the fund through wholly owned subsidiaries acting as general partner and advisers. Rajeev Misra was announced as CEO of the investment advisers and a member of the investment committee. SoftBank proposed contributing approximately 24.99% of Arm’s shares to satisfy about $8.2 billion of its commitment, subject to approvals and other preconditions. Arm would remain a consolidated subsidiary operating as a separate business within the group.[11]