SoftBank launches $11 billion bond sale to fund OpenAI investment

SoftBank is putting more than $11 billion of debt behind its OpenAI ambitions, turning one of tech’s biggest private-market bets into a potentially record-setting corporate bond sale.

The Japanese investment giant on Monday launched $10 billion in dollar-denominated senior unsecured notes and €1 billion, worth about $1.15 billion, in euro notes, according to a term sheet reviewed by Reuters. The money will help fund a $10 billion payment tied to SoftBank’s next investment in OpenAI, scheduled to close on October 1.

“The dollar-denominated notes are split into 3-1/2-year, 5-1/2-year and 7-1/2-year maturities, while the euro-denominated bonds are split into 4-year and ​6-year maturities,” Reuters reported.

The size alone puts the transaction in rare territory. If completed as planned, it would become the largest non-financial corporate bond offering ever from the Asia-Pacific and Japan region, topping 7-Eleven’s $10.93 billion deal in 2021, according to LSEG data cited by Reuters. Dealogic data would place it among the 20 largest corporate bond transactions globally this year.

The news comes just a week after SoftBank secured an $11.87 billion two-year loan from about 20 banks to help finance its massive OpenAI bet, just as investors sent the Japanese conglomerate’s shares down as much as 13%.

SoftBank is spreading the borrowing across several maturities. The dollar notes will run for 3.5, 5.5 and 7.5 years. The euro notes will mature in four and six years. Pricing is expected on September 24, followed by settlement on September 29.

The bond sale will replace a $10 billion bridge facility SoftBank arranged to finance the OpenAI investment. That shift matters. Bridge loans are typically short-term financing meant to carry a borrower until longer-term funding can be secured. SoftBank is now moving a major piece of its OpenAI financing into the bond market.

SoftBank’s OpenAI bet moves onto the balance sheet

The financing is part of a much larger commitment.

SoftBank agreed in February to invest another $30 billion in OpenAI through three $10 billion installments scheduled for April, July and October 2026. The company said completion of the full investment would bring its cumulative OpenAI investment to $64.6 billion and give it an ownership interest of about 13%.

That makes OpenAI one of the defining investments of Masayoshi Son’s latest AI push and raises the stakes for SoftBank’s financing strategy.

Fitch Ratings assigned the proposed notes a BB+ rating. The ratings firm expects SoftBank’s debt to increase as the company finances committed investments, yet said it expects the group to retain adequate liquidity and access to capital markets.

SoftBank has been signaling that refinancing its short-term OpenAI borrowing will be a major task this year. In its 2026 annual report, CFO Yoshimitsu Goto said the group planned to repay and refinance its bridge facility through several forms of longer-term financing. SoftBank reported a loan-to-value ratio of 17% as of March 31 and has maintained a policy of keeping that figure below 25% under normal market conditions.

Citigroup is leading the dollar bond offering, with JPMorgan leading the euro deal. Goldman Sachs, Morgan Stanley and Deutsche Bank are among the banks working on the transactions.

For SoftBank, the bond sale is more than another financing transaction. It shows just how much capital the company is prepared to commit to OpenAI, and how deeply that bet is becoming embedded in SoftBank’s own balance sheet.