SoftBank's Funding Jigsaw: A Trillion-Yen Bond, Nvidia Backing, and a Portfolio in Flux

SoftBank raises record ¥1tn bond, courts Nvidia backing, and trims TSMC stake to fund OpenAI commitments.

The arithmetic behind Masayoshi Son's artificial-intelligence ambitions is becoming increasingly visible — and increasingly demanding. SoftBank Group is simultaneously courting Japan's retail bond market, negotiating fresh backing from Nvidia, and quietly reshaping its US equity portfolio, all in service of the same overarching goal: keeping its multibillion-dollar commitment to OpenAI fully funded.

The most immediate test arrives on September 4, when the seven-year tranche of a ¥1 trillion bond — the largest ever issued by a Japanese corporate borrower — is slated to be priced with an indicative coupon range of 4.3 to 4.9 percent. The subscription window runs from September 7 through September 16, with issuance scheduled for the following day. SoftBank has stated explicitly that the proceeds will finance its investment pledges to OpenAI.

That record-breaking retail offering, however, is only one piece of a broader financing mosaic. Reuters reported that SoftBank is also in talks with investment banks about a potential dollar-denominated bond of $10 billion to $20 billion, intended to refinance a loan tied to its OpenAI exposure — a report the company has not confirmed. The timing is hardly coincidental: roughly ¥497.9 billion in existing bonds come due this September, and a $40 billion bridge loan linked to OpenAI matures in March 2027.

Nvidia Steps In — and In

The capital demands extend well beyond the bond markets. Nvidia has announced it will provide guarantees of up to $105 billion for the Ohio data-center project that OpenAI is developing with SB Energy, SoftBank's renewable-energy subsidiary, alongside a direct equity investment of $1.5 billion in SB Energy itself. That follows earlier reports that Nvidia was negotiating a stake of up to $3 billion in the subsidiary as part of broader financing discussions for OpenAI's data-center buildout.

The sums underscore how the AI push has become a balance-sheet event of historic proportions. SoftBank's commitments stretch across the Atlantic as well: at the Choose France summit in early June, the group signaled it could invest up to €75 billion in new European data centers.

A Portfolio Quietly Repositioned

To free up capital, SoftBank has been rotating its US equity holdings with notable speed. Regulatory filings for the quarter ended June 30 show the group sold 71.5 percent of its stake in Taiwan Semiconductor Manufacturing — roughly 1.4 million shares worth $269.8 million. In their place, SoftBank established a new position in Capital One, holding 276,811 shares valued at $55.5 million, plus a smaller stake in Life360 worth $488,500.

Intel remains the anchor of the US portfolio by a wide margin. The roughly 87 million shares held at the end of June — worth more than $12 billion — accounted for nearly 67 percent of the disclosed US holdings, and the position's recent strength helped the group's latest quarterly results come in better than feared.

The Operating Engine Keeps Running

Beneath the holding-company drama, the operational subsidiary SoftBank Corp. delivered a record first fiscal quarter, with revenue climbing 9 percent year over year to ¥1,814.7 billion. Operating income and net profit each advanced roughly 7 to 9 percent, evidence that the core business remains self-sustaining even as the parent company's valuation increasingly hinges on its investment bets.

The strategic build-out continues on multiple fronts. A newly formed entity, SB Neo, is tasked with establishing a neocloud business in the US, while in Japan a beta version of the Infrinia AI Cloud OS software is already running, with a full commercial launch targeted for fiscal 2027. The acquisition of DigitalBridge at $16.00 per share in cash, agreed in December 2025, is also approaching completion.

Market Temperament: Cautious

The share price has yet to show a decisive reaction to the refinancing news. The stock traded at €27.98 on Wednesday, up 0.7 percent after closing at €27.77 the prior day. Over 30 days, however, the shares are down roughly 4 percent, leaving the market capitalization at approximately €152.69 billion. The relative strength index of 42.3 points to neither overbought nor oversold conditions, while annualized volatility of around 73 percent captures the market's edginess about the scale of the AI wager.

Whether the OpenAI bet ultimately justifies the financing strain is a question that will be answered not at the September 4 pricing, but in the years ahead, as either the AI investments bear fruit or the interest burden tightens its grip. For now, the balance between opportunity and risk appears finely poised — and subject to revision with every new headline out of Tokyo.