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SoftBank Borrows $11.87 Billion to Fund Its OpenAI Bet

SoftBank and OpenAI signage representing SoftBank's debt-financed OpenAI investment
SoftBank is funding its OpenAI commitment through a stack of loans and bond sales rather than cash. Source: WSJ
Quick answer: SoftBank closed an upsized $11.87 billion two-year loan from roughly 20 banks in September 2026, raising it from an initial $10 billion target, to help fund its investment in OpenAI. The loan pushes SoftBank's total OpenAI commitment toward $65 billion by October, most of it borrowed through bonds and secured loans rather than paid in cash. SoftBank shares fell as much as 13 percent on September 14, the steepest drop since July, as investors priced the leverage behind a bet on a company that has just ruled out a near-term IPO.
TLDR

SoftBank upsizes an OpenAI loan to $11.87 billion

SoftBank sealed a syndicated loan of $11.87 billion, larger than the $10 billion it originally sought, with roughly 20 banks joining the two-year facility, according to Bloomberg. The financing is one piece of a funding push that Masayoshi Son has assembled to meet a commitment to OpenAI that is now approaching $65 billion, the largest single wager of SoftBank's history and one of the largest private technology bets on record.

The bet by the numbers
$11.87BUpsized two-year loan, raised from a $10B target
~20 banksLenders in the syndicated facility
~$65BTotal OpenAI commitment SoftBank is funding by October
~$37BAlready raised toward it through bonds and loans
13%Intraday fall in SoftBank shares on September 14, the worst since July 17

Masayoshi Son is financing the OpenAI stake with debt, not cash

The structure matters as much as the size. SoftBank is funding the OpenAI position through a stack of borrowings rather than from cash on hand, layering bond sales and secured loans on top of one another to reach the target. The pieces disclosed so far describe a company leaning heavily on leverage to buy into a single asset.

SoftBank's OpenAI financing stack
InstrumentSizeStructure and status
New syndicated loan$11.87BTwo-year facility, ~20 banks, closed September 2026
Margin loan$10BBacked by SoftBank's OpenAI stake
Junk bond saleup to $20BIn progress
Earlier bridge loan$40BObtained earlier in 2026, $25.9B balance due September 15
Horizontal bar chart of SoftBank's OpenAI financing stack in USD billions: new syndicated loan 11.87, earlier bridge loan 40 with 25.9 due September 15, junk bond sale up to 20, margin loan 10
SoftBank is funding its OpenAI commitment almost entirely through layered debt, refinanced on short cycles. Source: Santage analysis of Bloomberg and Japan Times reporting, September 2026.

This is the same playbook Son ran with the Vision Fund, concentrated into one name. Where the Vision Fund spread borrowed capital across dozens of startups, the OpenAI commitment routes the leverage into a single company that does not expect to turn a profit for years and that has now ruled out a near-term public listing. Sam Altman closed the exit himself this month.

I actually think that, given everything happening with safety, right now would be an ill-advised moment to go public. I would say not 2026.
Sam Altman, OpenAI CEO, Fortune interview, September 12, 2026

Altman's comment removes the cleanest path SoftBank had to mark and monetize the stake, which makes the debt behind it heavier rather than lighter. The broader financing wave sits alongside the $35 billion compute commitment Anthropic struck with Lambda, a sign that the capital intensity of frontier AI infrastructure is now measured in tens of billions per relationship.

A 13 percent share drop shows the market pricing the leverage

Investors reacted immediately. SoftBank stock fell as much as 13 percent on September 14, its worst session since July 17, even though the loan itself was a success by its own terms, oversubscribed and upsized. The market read the enlarged facility as confirmation of how much debt now stands behind the OpenAI position, and how exposed SoftBank's balance sheet has become to the fortunes of one private company.

The sell-off captures the central risk of the circular financing that now defines the AI build-out. SoftBank borrows to fund OpenAI, OpenAI commits that capital to compute providers, and those providers borrow against future AI demand to build the data centers. Each link is rational on its own, and the chain concentrates risk in a small number of names whose valuations depend on continued frontier progress. A durable slowdown in that progress would strain every link at once.

The repayment most coverage skipped: $25.9 billion due September 15

The number that frames the new loan is the one due the day after it was reported. SoftBank is repaying a $40 billion bridge loan taken earlier in the year, with a $25.9 billion balance falling due on September 15. The fresh $11.87 billion facility is not simply new firepower for OpenAI, it is part of the refinancing machinery that keeps an already heavy debt load rolling forward. Read against that repayment, the upsized loan looks less like expansion and more like the cost of staying in the position.

SoftBank's OpenAI bet may still prove to be the defining investment of the AI era. What this week established is the price of holding it: roughly $65 billion committed, most of it borrowed, refinanced on two-year cycles, and marked to a company that will not go public while the debt behind it is denominated in tens of billions and repriced every time the market questions the pace of AI itself.

In short: SoftBank's upsized $11.87 billion loan pushes its OpenAI commitment toward $65 billion, funded almost entirely with debt and refinanced on two-year cycles, just as a $25.9 billion bridge-loan balance comes due and OpenAI rules out a near-term IPO. A 13 percent share drop shows the market pricing the leverage in the circular financing chain that now runs from SoftBank through OpenAI to the compute providers building AI's data centers.
Editor's note

Loan terms, the financing stack, and the share reaction are drawn from Bloomberg and Japan Times reporting on SoftBank's September 2026 filings. Sam Altman's remarks are quoted verbatim from his September 12, 2026 interview with Fortune. Figures are as reported at publication and may be revised as SoftBank completes the remaining tranches.

Santage is committed to independent, transparent journalism. This article is produced in accordance with Santage's Editorial Standards and aims to provide accurate and timely information. Readers are encouraged to verify information independently.