HSBC, BNP Paribas, and Intesa Sanpaolo are among eight institutions that have submitted commitments as sub-underwriters, in one of the largest tests of creditor appetite for AI-linked debt.

The $40 billion bridge loan SoftBank signed in March to fund its investment in OpenAI is attracting more lenders, with at least eight banks now having submitted commitments as sub-underwriters as of late last week, according to Bloomberg.

New joiners include HSBC, BNP Paribas, and Intesa Sanpaolo, who are participating alongside the original underwriters in a syndication process that is now in what Bloomberg describes as a ‘soft launch’ phase.

The loan itself is one of the most consequential pieces of financing in the current AI boom. Signed on 27 March 2026, it is an unsecured, 12-month bridge facility underwritten by JPMorgan Chase, Goldman Sachs, Mizuho Bank, Sumitomo Mitsui Banking, and MUFG Bank.

SoftBank used the proceeds primarily to fund its $30 billion follow-on investment in OpenAI through Vision Fund 2, as part of OpenAI’s $110 billion funding round, the largest private funding round in history, which valued OpenAI at $852 billion. SoftBank’s total investment in OpenAI now stands at approximately $64.6 billion.

What the loan structure signals about the OpenAI IPO?

The 12-month unsecured structure is designed to be short. SoftBank must repay or refinance by 26 March 2027. The loan is unsecured, it is not backed by SoftBank’s OpenAI shares, its Arm Holdings stake, or any other specific collateral, which means lenders are taking a view on SoftBank’s overall creditworthiness and, implicitly, on the likelihood of a liquidity event that gives the group the resources to repay.

That liquidity event is almost certainly an OpenAI IPO. As TechCrunch has noted, the 12-month maturity strongly implies that the original lenders, and now the sub-underwriters joining the syndicate, expect OpenAI to list within the next year, giving SoftBank the liquidity to retire the debt.

OpenAI is widely reported to be targeting an IPO as early as Q4 2026, which would be one of the largest public offerings in technology history. If the IPO slips or is delayed, SoftBank faces significant refinancing pressure: an S&P credit outlook downgrade to negative in March flagged the concentration risk, noting OpenAI could represent approximately 30% of SoftBank’s portfolio.

SoftBank’s debt-fuelled AI push extends beyond this loan. The group is also in discussions to raise a separate $10 billion margin loan backed by its OpenAI shares as collateral.

Together, these financing arrangements represent one of the most heavily leveraged bets on a single private company in modern financial history, and the breadth of the bank syndicate now forming around the $40 billion facility, spanning US, European, and Japanese institutions, is itself a statement of creditor confidence in the OpenAI story, or at least in SoftBank’s ability to manage the exposure.

The arithmetic behind SoftBank’s AI bet

The scale of SoftBank’s commitment to OpenAI is difficult to overstate. Masayoshi Son’s $100 billion infrastructure pledge in the US, announced with then President-elect Trump in December 2024, created the political momentum that preceded the investment.

OpenAI’s February 2026 funding round, in which Amazon committed $50 billion, Nvidia $30 billion, and SoftBank $30 billion, brought SoftBank’s cumulative OpenAI stake to a figure one analyst estimated at approximately $64.6 billion.

Against that position, the $40 billion loan, now being distributed to a broader creditor base including three prominent European banks, is structurally analogous to a margin call facility: a way for Son to continue expanding the position without liquidating other assets, betting that the OpenAI IPO will provide a windfall large enough to settle the debt comfortably.

The arrival of HSBC, BNP Paribas, and Intesa Sanpaolo in the syndicate suggests that European banks, too, are willing to take that bet.