Inside SoftBank’s $60 Billion AI Wager: The Balance-Sheet Risks and the Race for an OpenAI IPO

SoftBank Group has placed the largest single-asset bet in its history on OpenAI, committing more than $60 billion to the artificial intelligence company. This wager has reshaped the Japanese conglomerate’s portfolio—and introduced acute financial risks that have attracted sharp scrutiny from credit rating agencies, equity analysts, and investors. The strategy ultimately depends on a successful public listing of OpenAI on favorable terms, a dependency that is now testing the limits of SoftBank’s balance sheet.

Rating Agencies Sound the Alarm

S&P Global Ratings shifted SoftBank Group’s credit outlook from stable to negative in March 2026. The agency warned that the company’s “asset liquidity, portfolio quality and financial capacity are likely to deteriorate” as a direct result of the additional OpenAI investment . S&P noted that OpenAI now constitutes a disproportionate share of the group’s portfolio and identified it as an investment with the “weakest credit quality” .

The Japan Credit Rating Agency (JCR) moved earlier, revising its outlook for SoftBank’s “A” long-term rating from stable to negative in April 2025. JCR explicitly cited the rising proportion of unlisted AI assets as a driver of increased equity-value fluctuation risk . While neither agency has yet downgraded the core ratings, the negative outlooks signal that further deterioration is a distinct possibility if liquidity continues to tighten.

Jefferies: “Underperform” and a ¥3,140 Target

The most pointed equity-side warning came from Jefferies, which downgraded SoftBank to “Underperform” and slashed its price target from ¥5,118 to ¥3,140—a level that implied roughly 19% downside from the prevailing share price .

Jefferies’ thesis raises three structural concerns:

• Valuation integrity: Because SoftBank supplied approximately 85% of the capital in OpenAI’s recent funding rounds, the bank argues that the rising private valuation—which has climbed from $150 billion to over $800 billion—is substantially self-funded and inflates SoftBank’s own reported net asset value .
• Concentrated exposure: The OpenAI position has ballooned to nearly a third of SoftBank’s total investment assets. More than 50% of its portfolio is held in illiquid private-market instruments, making the group’s balance sheet unusually brittle .
• Related-party payments: SoftBank pays OpenAI roughly $3 billion per year for services in Japan, while paying approximately $200 million to Arm Holdings quarterly—a figure that represents about 16% of Arm’s revenue. These flows create a self-reinforcing loop and have drawn corporate-governance questions .

How the $40 Billion Bridge Loan Turned Into an IPO Bet

To fund successive rounds of OpenAI investment, SoftBank raised a $40 billion unsecured bridge loan . The debt was structured on the expectation that OpenAI would soon go public, providing a liquid exit at or above the $730–$840 billion valuation range set by private fundraising rounds .

If an IPO materializes at those levels, SoftBank can sell down part of its stake and comfortably service the loan. If the listing is delayed or prices lower than anticipated, SoftBank faces a gaping funding hole. Analysts estimate a ~$32 billion shortfall under a scenario where SoftBank must fully fund its remaining OpenAI tranches and Stargate data-center commitments without an equity market exit .

The exposure is enormous in absolute terms: by late March 2026, SoftBank’s OpenAI position was valued at roughly $79.6 billion, representing a $45 billion floating profit on paper . TD Cowen pegged the 11% stake at about $80 billion, but cautioned that the valuation is entirely untested by public markets .

Liquidity, Leverage, and the Wider Portfolio

The raw numbers paint a picture of a balance sheet stretched thin:

• OpenAI represents approximately 30% of SoftBank’s investment assets .
• Over 50% of the $320 billion portfolio consists of illiquid private assets .
• SoftBank’s loan-to-value ratio has expanded beyond historical comfort levels, with internal leverage estimated to have risen from roughly 16.5% to around 21.5% by December 2025 .

S&P has stated explicitly that the group’s liquidity and creditworthiness are likely to remain materially weakened for the foreseeable future, barring decisive asset sales or a swift public listing of the concentrated holdings .

Stock Volatility and a “Valuation Trap”

SoftBank shares have experienced sharp swings. The stock plunged 9.8% after the Stargate joint venture with Oracle collapsed, and by late March 2026 it was down nearly 45% from its October 2025 highs . While a rally into the May 2026 earnings report recaptured some ground, volatility remains elevated .

Jefferies went so far as to label SoftBank a “valuation trap,” warning that the premium attributed to the OpenAI stake may not survive contact with public-market scrutiny . The underlying concern is that the current private-mark valuation relies on SoftBank’s own capital recycling through ever-higher fundraisings—a loop that a public listing could break, rather than validate.

The IPO Dependency in Context

SoftBank’s entire capital structure now rests on an OpenAI IPO thesis . The $40 billion bridge loan is unsecured, and without a successful listing, the most viable repayment paths would likely involve selling down stakes in Arm or other core holdings—moves that could trigger a downward reassessment of the group’s entire portfolio value. Rating agencies and analysts alike have flagged that the combination of extreme concentration, rising leverage, and the absence of a clear near-term liquidity event places SoftBank’s credit profile in unusually vulnerable territory .

For now, SoftBank’s management emphasizes that its loan-to-value policy remains below 25% and that it holds sufficient cash to cover two years of bond redemptions . But those defenses rely on marks that a public market has yet to confirm—and on an IPO window that remains uncertain amid intensifying competition in the AI space.