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SoftBank paid its last $10 billion into OpenAI with an $11.1 billion high-yield bond sale
SoftBank sold $11.1 billion of high-yield bonds, a record by CNBC's count, to pay the final $10 billion of its $30 billion OpenAI commitment. The debt sits with a BB+ borrower, so credit conditions reach OpenAI's money through one investor's balance sheet.
The Scientist · Science desk
What happened
- SoftBank's commitment was split into three equal $10 billion tranches due April 1, July 1 and October 1, 2026, and the first two had landed by July.
- The offering paired $10 billion of dollar senior unsecured notes with 1 billion euros of euro notes, launching September 21 and settling September 29.
- On September 29, OpenAI cut GPT-6.1 Sol to $2 per million input tokens and $10 per million output tokens, half its price of a week earlier.
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Why it matters
- exposure Japanese savers who bought SoftBank's retail bonds now hold credit risk in a company that has put about $64.6 billion into one private AI lab.
- constraint SoftBank's room to keep funding OpenAI is tied to a private $852 billion mark, and a lower round would shrink the paper value behind its borrowing.
- precedent An oversubscribed $11.1 billion sale by a BB+ issuer shows high-yield buyers will fund equity commitments to an AI lab, a route other backers can now cite.
Of OpenAI's $122 billion round, which closed on March 31 [6], the bond-funded tranche is about 8% [1]. SoftBank's full $30 billion commitment is roughly a quarter of it [2]. Forkast reports that SoftBank did not pay the third tranche from operating cash flow or asset sales [5]. It does not report the coupon on the notes, or how SoftBank's first two tranches and the $50 billion from Amazon and $30 billion from NVIDIA were funded [17].
The borrowing sits at SoftBank. The dollar notes are SoftBank's senior unsecured debt [4], and Forkast puts the company at BB+, "deep into high-yield territory" [8]. OpenAI receives an ownership stake [15]. I think AI funding is exposed to credit conditions here, but one step removed. Higher borrowing costs land on SoftBank first. They reach OpenAI only through what SoftBank can commit next time.
Together with the 1 trillion yen of retail bonds, SoftBank placed roughly $17.4 billion of debt in September [4]. Because the notes are unsecured, buyers are lending against SoftBank as a whole, and its OpenAI position is a private holding. SoftBank has paid about $64.6 billion for an estimated 13% of OpenAI [15]. At the $852 billion post-money valuation [6], 13% is worth about $111 billion on paper [3]. A private round set that price. The OpenAI Foundation keeps 26% and appoints every member of the PBC board [16], so the stake does not bring control of the board.
Forkast wrote: "This is no longer venture capital. It is infrastructure-grade financing, priced and sold like sovereign debt for a new asset class." [10] The publication's own figures argue with the second sentence. A BB+ issuer borrows in the high-yield market [8], and the record CNBC cited is a high-yield record [3]. Oversubscription, which Forkast reports [9], shows that buyers wanted the paper. It does not show the price was low.
Forkast also says OpenAI's September 29 launches, the Sol price cut and the $500-a-month Dots tier among them, were funded "directly or indirectly" by this capital base [13][14]. The launches fell on the day the notes settled [4]. Matching dates do not show that bond proceeds bought cheaper tokens. Cash inside OpenAI is fungible, and a token price cut is a decision about inference margins. A $10 billion equity tranche could just as well be paying for training, and the timing does not separate the two.
What to watch
- How the new SoftBank notes trade after settlement; wider spreads would put a price on lenders' view of a concentrated OpenAI bet.
- Any disclosure that Amazon or NVIDIA borrowed to fund their OpenAI commitments; that would push the debt-funded share of the round beyond one tranche.
- OpenAI's next priced round, where a valuation below $852 billion would cut the paper value of the stake SoftBank borrowed against.