SoftBank's OpenAI Stake Just Became $10 Billion of Leverage

SoftBank has done something close to impossible: it borrowed $10 billion against its shares in a private company. In early August, Goldman Sachs, JPMorgan, Mizuho, Apollo, and Sumitomo Mitsui closed a two-year loan secured by SoftBank's stake in OpenAI — but only on conditions that reveal how they really rate that collateral. SoftBank must guarantee repayment from the parent company's balance sheet, and it must inject more cash if OpenAI's shares lose value.

The structure is the story. A margin loan works because the lender can sell what it holds: public shares trade daily, so the day you stop paying, the bank dumps the stock and collects. OpenAI has no ticker, no daily price, no line of buyers waiting to take a position in a privately held, cash-burning company at a moment's notice. There is no market to sell into. That is the entire reason the deal took months, and why the banks only signed after SoftBank put the whole company's balance sheet behind it.

This matters even if you never plan to buy SoftBank stock. SoftBank — U.S. ticker SFTBY — is the public market's most direct way to own the outcome of OpenAI. It has now put $64.6 billion into the ChatGPT maker for roughly 13% of the company, with a final $10 billion installment due October 1. At the $840 billion valuation set in February, when Amazon, Nvidia, and SoftBank poured $110 billion into the company, the stake marks at about $110 billion against a $64.6 billion cost. OpenAI's revenue is running above $40 billion a year, nearly double its pace at the end of 2025. On that surface, this looks like a masterpiece: own the central company of the biggest technology shift since the internet, paid for at roughly 60 cents on the current dollar.

The debt underneath tells a colder story. That margin loan sits on top of a $40 billion bridge loan SoftBank raised this year to help fund its OpenAI purchases, and the bridge has to be repaid by March 2027. Which is why, this week, SoftBank began discussing a $10 billion to $20 billion bond sale in dollars and euros, possibly as soon as September, to roll the bridge into longer-term debt. In the same stretch it sold a record ¥1 trillion of retail bonds in Japan. In April, SoftBank paid 8.5% on a ten-year dollar tranche — the highest coupon it has ever paid on such a bond — using the proceeds to repay OpenAI-related bridge loans. The borrowing machine is running hot, and the interest bill is climbing at the same moment the stock trades at a discount.

The agencies see it too. S&P cut SoftBank's credit outlook to negative in March, citing the liquidity and asset-quality risk of the OpenAI investments, and Fitch has warned that an AI price correction would hurt the companies that borrowed to build it. The market already prices part of that in: SoftBank's net asset value sits near a record, roughly ¥40 trillion or about $260 billion, while the stock trades about 46% below that number.

State the bull case fairly, because it is not crazy. OpenAI is growing revenue faster than almost any company in history, though it still burned $3.7 billion in the first quarter of 2026. And that $840 billion mark is not a market price; it is an agreement among people with reasons to be generous. Amazon put up $50 billion in the same round. Nvidia put up $30 billion while serving as its main chip supplier. SoftBank put up $30 billion to support the worth of its own holding. That is a room of investors marking their own asset — the circular-financing pattern Wall Street has flagged, in which firms invest in and sign supply deals with one another. The debt market is the more honest instrument, and its verdict was visible the moment lenders refused to hold OpenAI's private shares as collateral without a SoftBank guarantee. Nobody lends that way when they think the collateral is underpriced.

The resolution is an IPO. OpenAI filed confidentially for a U.S. listing this summer, and a public debut would convert SoftBank's preferred shares into common stock that trades daily and can actually be sold — precisely the thing the lenders said the collateral was missing. It is also the most plausible path to closing that 46% discount. Until then, the position is a private mark held together by borrowed money. One downward repricing triggers the cash calls. The short-dated bridges have to be rolled at record coupons. And a stake marked at $110 billion on paper cannot be turned into $110 billion in cash on any schedule SoftBank controls.

This is the abundance-scarcity paradox doing real work. When capital is abundant — roughly $400 billion of AI-infrastructure bonds issued so far this year — what investors chase is scarcity, and frontier AI equity is about as scarce as any asset gets. SoftBank built the most concentrated public wrapper for that scarcity and then financed it with leverage. Leverage is exactly why the stock trades at half its net asset value, and exactly why the discount may be deserved. Three numbers are competing: the private mark says the stake is worth about $110 billion; the lenders say they would rather hold a guarantee than the shares; the stock market says 46% off. If OpenAI's IPO prices below the $840 billion mark, the private number that justified the whole stack fails its first public test, and the spread between those numbers is where the risk has been living all along.