SoftBank sells a record $11.1 billion of junk bonds to fund its OpenAI bet

SoftBank Group has raised $11.1 billion in dollar- and euro-denominated bonds, the largest high-yield corporate bond sale globally on record, to keep funding its enormous bet on OpenAI.

The deal

According to Reuters and The Japan Times:

• $10 billion of dollar-denominated senior unsecured notes, plus
• €1 billion (about $1.15 billion) of euro-denominated notes,
• split across five tranches maturing in 3.5 to 7.5 years.

“High-yield”, or “junk”, means the bonds are rated below investment grade, so SoftBank pays higher interest than a top-rated company would to compensate investors for extra risk. The Japan Times described the yields as a steep price to pay.

What the money is for

The proceeds will finance SoftBank’s next $10 billion tranche of investment in OpenAI and replace bridge financing, short-term loans taken out while longer-term funding was arranged.

Once SoftBank completes its $30 billion follow-on investment, its total investment in OpenAI would reach $64.6 billion, for an expected ownership stake of about 13%, according to reports.

A pattern of borrowing

This is not SoftBank’s only recent trip to the bond market:

• It has issued $14.6 billion of high-yield bonds so far in 2026, which reports say accounts for 63.4% of the Asia-Pacific and Japan high-yield corporate bond market.
• Earlier this month it sold a ¥1 trillion (about $6.3 billion) bond issue aimed at retail investors in Japan.

The risk

Financing an equity stake in a private company with public debt concentrates risk. SoftBank’s finances look sound while enthusiasm for OpenAI and AI in general stays high. Analysts quoted in coverage warn that the picture could change quickly if market sentiment toward OpenAI, or the AI sector more broadly, weakened significantly, leaving SoftBank with fixed interest bills on a stake whose value had fallen.

For now, investors lined up to lend. That, more than anything, says how much appetite remains for a piece of the AI boom.