SoftBank raises $11.1B through junk bonds to fund its OpenAI bet

SoftBank Group has raised $11.1 billion through a sale of dollar- and euro-denominated senior notes, the company said, in one of the largest junk-bond offerings on record. The money will fund the final part of the Japanese conglomerate's investment in OpenAI.

The proceeds cover a $10 billion payment — the third and final tranche of a $30 billion follow-on investment in OpenAI agreed in February, expected to close on October 1. That brings SoftBank's total commitment to the ChatGPT maker to $64.6 billion, for a stake of roughly 13%.

One of the biggest junk deals on record

The dollar portion is split into three tranches: $1 billion due in 3.5 years at 8.625%, $4.5 billion due in 5.5 years at 9.25% and $4.5 billion due in 7.5 years at 9.75%. Two €500 million euro tranches, with four- and six-year terms, pay 7.125% and 8%. The total is worth about ¥1.76 trillion. Demand during bookbuilding topped $20 billion, and the company said it will not increase the size beyond the planned $10 billion plus €1 billion.

Borrowing on several fronts

According to Bloomberg-compiled data, the sale makes SoftBank the biggest corporate junk-bond borrower in the world; the group has already sold almost $15 billion of notes across currencies this year, the most of any speculative-grade borrower in 2026. The bond sale is only one piece of its financing push: in March SoftBank arranged a $40 billion bridge facility for its OpenAI investments and repaid the $25.9 billion outstanding on it this month, while the remaining $10 billion of undrawn capacity will be cancelled alongside the new deal. The group also increased a margin loan backed by Arm shares by $5 billion to $25 billion, and Apollo Global Management is in talks to raise a separate loan by $3.6 billion, to as much as $9 billion, on top of an $11.87 billion facility secured this month.

Why it matters

SoftBank is rated BB+ by S&P and Fitch — just below investment grade — and the deal shows how much capital the AI race now demands. The yield on its 2031 dollar bond climbed to 8.2% this month from as low as 6.7% in January, and the cost of insuring its debt against default hit a three-year high amid concerns about slowing AI spending. Yet record-high coupons drew strong demand, and SoftBank shares jumped more than 7% in Tokyo, where trading opened for the first time this week after a three-day holiday.