SoftBank Closes Third $10B OpenAI Tranche Using Senior Notes Proceeds

SoftBank Group Corp. said in an October 1, 2026 announcement that it executed the third and final $10 billion tranche of its follow-on investment in OpenAI Group PBC, completing the $30 billion program announced in February 2026 and bringing its cumulative investment in the AI company to $64.6 billion for an ownership interest of approximately 13%. The tranche was executed on October 1, 2026 (Japan time) through SoftBank Vision Fund 2 and amounted to JPY 1,579.6 billion, converted at JPY 157.96 per dollar.

SoftBank said it was funded with proceeds from a foreign currency-denominated senior notes issuance whose terms the company set on September 24, 2026. SoftBank entered the definitive agreement with OpenAI Group PBC, a U.S.-based company, on February 27, 2026 (U.S. time), committing to participate in OpenAI’s fundraising round with follow-on investments totaling $30 billion, or JPY 4,674.3 billion at JPY 155.81 per dollar, through SoftBank Vision Fund 2.

The investment was priced at a pre-money valuation of $730 billion and divided into three $10 billion tranches scheduled for April 1, July 1, and October 1, 2026 (Japan…