SoftBank Group said it completed an additional $22.5 billion investment in OpenAI on Dec. 26, closing out a financing package that SoftBank first committed to in March 2025. With the latest closing, SoftBank said its aggregate ownership interest is now approximately 11%, and that the broader financing round totals $41.0 billion when including $11.0 billion from third-party coinvestors.

According to SoftBank, the investment was executed in multiple tranches through SoftBank Vision Fund 2. The company said it completed a first closing in April 2025, investing $7.5 billion, and funded the second closing in December. SoftBank said the Dec. 26 funding satisfies its previously announced commitment “to invest in OpenAI” in March.

In its April 1 release describing the agreement, SoftBank said the commitment was up to $40.0 billion, and that it planned to syndicate up to $10.0 billion to coinvestors, putting SoftBank’s expected “effective investment amount” at up to $30.0 billion. That disclosure also outlined SoftBank’s financial policy for loan-to-value management and cash positioning.

Stargate context

SoftBank tied the OpenAI financing to its role in Stargate, a U.S.-based AI infrastructure effort announced with OpenAI earlier in 2025. OpenAI described Stargate as a new company intended to invest up to $500 billion over four years to build AI infrastructure for OpenAI in the U.S., with $100 billion planned for immediate deployment.

OpenAI said the initial equity funders are SoftBank, OpenAI, Oracle and MGX, with SoftBank holding “financial responsibility” and OpenAI “operational responsibility,” and SoftBank CEO Masayoshi Son serving as chairman.

Since the initial announcement, OpenAI has published milestones on Stargate’s capacity and site selection. In July, OpenAI said it had entered an agreement with Oracle to develop 4.5 gigawatts of additional Stargate data center capacity in the U.S., which would bring total capacity under development to more than 5 gigawatts and advance progress toward the 10-gigawatt commitment announced in January.

In September, OpenAI said that together with Oracle and SoftBank, it had selected five additional U.S. sites. OpenAI said those locations, plus the flagship Abilene, Texas buildout and other ongoing projects, would bring Stargate to nearly 7 gigawatts of planned capacity and more than $400 billion in investment over the next three years. OpenAI also said this put the partners “on a clear path” to securing the full $500 billion, 10-gigawatt commitment by the end of 2025.

Company statements

SoftBank’s Dec. 31 statement included comments from Son and OpenAI CEO Sam Altman characterizing the investment as aligned to OpenAI’s stated mission and intended to help OpenAI move faster. SoftBank did not disclose additional operating metrics or commercial terms beyond the funding amounts and ownership percentage.