Inside SoftBank's Stalled $6 Billion OpenAI Bet: Lenders Balk at an $850 Billion Question Mark

The core problem: valuing an $850 billion question mark

Lenders did not balk at a single deal term; they balked at the fundamental nature of the collateral itself. Margin loans require liquid assets with a clear, transparent market price. OpenAI, despite its towering status, is still a private company. This forces banks to estimate its value based on the latest primary funding rounds or secondary market agreements, a process that lacks the certainty of a public stock ticker .

Several factors made that estimation difficult:

• A floating valuation : OpenAI was last valued at roughly $852 billion in a funding round in March 2026. However, shares later changed hands on secondary markets closer to $880 billion, while earlier media reports floated the possibility of a future $1 trillion valuation . This moving target complicates any collateral calculation.
• No public financials : Banks were being asked to lend billions against a company whose detailed revenue, margins, and cost structure were not publicly available. A company's valuation is only as good as the numbers behind it, and those numbers remained locked in a vault .
• A structural mismatch : As one report bluntly summarized, "this type of financing, common in publicly traded companies, is unusual in private firms like OpenAI, where the asset's value depends on the bank's judgment" .

How the confidential IPO amplified the uncertainty

OpenAI confidentially filed its S-1 registration statement with the SEC on June 8, 2026 . The filing, led by Goldman Sachs and Morgan Stanley, targeted a potential market debut as early as September 2026, with a valuation range of roughly $730 billion to $850 billion .

At first glance, an IPO filing seems like a step toward resolving the valuation uncertainty that was giving lenders cold feet. Instead, the confidential nature of the process amplified the problem. Because the S-1 was confidential, the filing itself did not immediately release audited revenue data or financial details to the public . Lenders were left in a holding pattern: they knew a definitive public valuation was coming but didn't yet have the hard data needed to underwrite a massive loan today. The IPO process may eventually resolve the valuation question, but until the registration statement becomes public and the offering is priced, it simply underlines how much remains unknown .

OpenAI itself added to the uncertainty when it filed, stating in a blog post that it had "not decided on timing yet; it may be a while because there are things we want to do that are likely easier as a private company" .

A piece of a much larger debt-fueled AI bet

The stalled margin loan is not SoftBank's only, or even its primary, financing vehicle for its AI ambitions. It is part of an extraordinary, multi-layered debt strategy led by CEO Masayoshi Son.

The $40 billion bridge loan. On March 27, 2026, SoftBank secured a massive $40 billion non-collateralized bridge loan, a record for the company . The twelve-month facility, maturing in March 2027, was explicitly taken out to fund SoftBank's $30 billion follow-on investment in OpenAI through its Vision Fund 2 . The initial underwriting syndicate included JPMorgan Chase, Goldman Sachs, Mizuho Bank, Sumitomo Mitsui Banking Corporation, and MUFG Bank, and later expanded to include at least eight banks as sub-underwriters .

Where the margin loan fit. The proposed OpenAI-backed margin loan was intended as an additional layer of leverage on top of this bridge financing. While the $40 billion bridge loan was unsecured corporate debt, the margin loan was supposed to be backed directly by SoftBank's equity in the AI company . The stall of the margin loan shows that while global banks are clearly willing to lend SoftBank massive sums based on its own credit profile, they are far more cautious when the deal is directly collateralized by a hard-to-value, pre-IPO stake in a company losing $2.20 for every $1 earned .

SoftBank's cumulative committed exposure to OpenAI now reaches roughly $64.6 billion, giving the group about 13% of the company . The ability to continue funding that exposure through creative debt structures is now a central question for investors and the banks underwriting these historic deals.