SoftBank Sells $11B in Bonds to Fund Its OpenAI Tranche

SoftBank Group has launched a bond sale of roughly $11 billion to pay for the last instalment of its stake-building in OpenAI. According to a term sheet seen by Reuters, the Japanese group is offering $10 billion and €1 billion of senior unsecured notes, with the proceeds earmarked for the $10 billion third tranche of its follow-on investment in OpenAI and for general corporate purposes.

The dollar notes are split across three maturities — 3.5, 5.5 and 7.5 years — while the euro portion comes in four-year and six-year tenors. The books are expected to price on 24 September and settle on 29 September, with Citigroup and JPMorgan as lead bookrunners. SoftBank had already secured a $10 billion bridge loan facility to cover the payment; the bond proceeds are set to replace that financing, swapping a short-term bank facility for term debt held by investors.

The payment itself is the closing act of a deal SoftBank announced on 27 February. That agreement committed $30 billion through SoftBank Vision Fund 2, structured as three equal quarterly tranches: $10 billion on 1 April, $10 billion on 1 July, and $10 billion due to close on 1 October. The investment buys preferred shares at a $730 billion pre-money valuation, which convert automatically into common stock on an OpenAI listing.

When the third tranche settles, SoftBank's cumulative investment in OpenAI reaches $64.6 billion — the $30 billion follow-on on top of $34.6 billion put in through Vision Fund 2 since September 2024 — for an ownership interest of roughly 13%. That makes SoftBank the largest outside shareholder in the company by some distance, and it makes the group's balance sheet unusually exposed to a single private position.

The financing structure is the part worth watching. SoftBank is rated below investment grade, so this is a high-yield deal, and at roughly $11 billion it ranks among the largest junk-bond sales ever raised by a single company outside of distressed debt exchanges. The group is, in plain terms, borrowing in the public debt markets to buy equity in a private company whose shares it cannot sell until an IPO — a trade that works cleanly if OpenAI lists at or above the $730 billion mark, and considerably less cleanly if the listing slips or reprices.