Shares of the Japanese holding company jumped more than 7% on Wednesday after it tapped the debt markets to secure the capital needed for its interest in the creators of ChatGPT. SoftBank is issuing $10 billion in dollar-denominated notes and €1 billion in euro bonds, totaling approximately $11.1 billion. The conglomerate will use the proceeds to complete a $10 billion payment to OpenAI by Oct. 1 and to replace an existing bridge facility of the same size.

The issuance ranks as one of the largest junk bond offerings by a single company ever, drawing over $20 billion in preliminary investor demand. SoftBank has committed nearly $65 billion to OpenAI in total, which will grant the investor roughly a 13% stake in the AI firm upon completion. This deal follows a laarge scale financing effort in 2026 where SoftBank has already sold about $15 billion in junk-rated bonds to fuel its AI strategy.