SoftBank Group Corp., led by legendary investor Masayoshi Son, is concentrating its capital allocation efforts heavily on AI application leader OpenAI and the associated AI computing infrastructure buildout. According to sources familiar with the matter, a bond issuance by SoftBank that could rank among the largest junk bond deals in global bond market history has attracted over $20 billion in preliminary subscription demand. Investors are rushing to lock in what could be record-breaking yields from this offering, with the proceeds earmarked to support the Japanese investment giant's massive investment in OpenAI.
Based on a disclosure announcement from SoftBank, cumulative investment in OpenAI is expected to reach $64.6 billion with a roughly 13% stake after this round of additional funding. Meanwhile, SoftBank is raising capital through near-90% pledged loans on its Arm Holdings shares, bank credit facilities, and large-scale bond issuances, while accelerating the "Stargate" AI data center project — described as a "Manhattan Project" for AI — alongside partners such as Oracle Corporation to support the AI computing infrastructure behind OpenAI.
Back in 2000, Son made his first investment of approximately $20 million in Alibaba, and through long-term shareholding, shared in the record-breaking value growth of the Chinese e-commerce platform as it transitioned from massive early-stage losses to the global capital markets spotlight — an investment legend. Today, Son believes OpenAI, which he is backing with substantial funds, holds similarly unparalleled growth potential as a mass-scale user gateway and enterprise technology platform.
Overwhelming Demand: SoftBank Junk Bond Sale Attracts Over $20 Billion in Preliminary Orders
Sources say a SoftBank bond issuance that could become one of the largest junk bond transactions in history has already attracted more than $20 billion in preliminary subscription interest. Investors are competing to secure the potentially record yields this offering may provide, with the funds intended to support the company's investment in OpenAI.
These sources noted that the demand reflects early, non-binding investor indications of interest, serving as a preliminary gauge of demand before pricing, with pricing still expected on Thursday. The individuals requested anonymity as the discussions involve private matters. Other sources said on Monday that SoftBank is seeking to raise over $11 billion equivalent through this transaction, including a $10 billion dollar-denominated tranche and a 1 billion euro tranche, approximately $1.1 billion. They added that the issue size has no cap, and no final decision has been made yet.
A SoftBank representative responded via email to inquiries: "The size of this issuance we launched is $10 billion and 1 billion euros. The transaction is proceeding very smoothly with strong demand. Any other statements about transaction size are purely speculative, and we have no plans to expand the offering." The group under billionaire Son has committed close to $65 billion in investments to OpenAI, the developer of ChatGPT, and combined with its other investments in the field, makes SoftBank one of the world's largest AI investors.
At a time when AI's potential and risks are increasingly amplifying global market volatility, these factors make SoftBank's junk bond deal one of the most significant tests of investor sentiment toward AI to date. Other sources said on Monday that SoftBank and its lead banks had been gauging potential pricing with investors. For the longest-dated dollar tranche of 7.5 years, the potential yield under discussion was approximately 10% at the high end; for the longest-dated euro tranche of 6 years, the yield discussion level was around 8.5%.
If ultimately priced at these levels, those indicative inquiry levels, along with those of other tranches, would set yield records across respective currencies and maturities. However, specifics may change, and the transaction has not yet entered the initial price guidance stage, which typically occurs closer to actual pricing; initial price guidance itself may not necessarily reflect final pricing levels.
Sources indicated SoftBank held a conference call for global investors on Monday and will continue on Tuesday. Citigroup is serving as lead bookrunner for the dollar tranche and is joint global coordinator alongside Goldman Sachs Group, JPMorgan Chase, and Morgan Stanley. JPMorgan is leading the euro-denominated bond bookrunning and serves as joint global coordinator with Goldman Sachs and Deutsche Bank. Citigroup, Goldman Sachs, JPMorgan, and Deutsche Bank declined to comment, while Morgan Stanley did not immediately respond to requests for comment.
As SoftBank expands its AI financing capacity, this latest transaction adds to a series of intensive financing activities in recent months. The group signed a $40 billion bridge loan facility in March to support its additional investment in OpenAI and recently repaid $25.9 billion of outstanding balance under that facility. As of the end of last week, the group had secured or was in the process of raising nearly $21 billion in potential new borrowings.
Sources said on Friday that the group increased its margin loan backed by shares of chip company Arm Holdings by $5 billion to $25 billion. Additionally, SoftBank recently increased an existing credit facility by $450 million, bringing the total to $6.5 billion. Apollo Global Management is also in talks to increase its loan to SoftBank by $3.6 billion to $9 billion to help finance the investment in AI giant OpenAI. Beyond that, the company founded and led by billionaire Son has secured an $11.87 billion loan, also in support of its OpenAI investment, according to people familiar with the transaction.
Data compiled by Bloomberg shows that as part of this year's financing actions, SoftBank has issued nearly $15 billion equivalent in bonds denominated in various currencies, making it the largest junk-grade borrower in the bond market year-to-date for 2026. Earlier this year, SoftBank also secured a $10 billion loan collateralized by its OpenAI stake. These transactions occur as most major economies grapple with inflation, with borrowing costs generally rising across markets.
Bloomberg-compiled data indicates that as credit spreads widened and Treasury yields, the pricing benchmark, rose, the yield on SoftBank's 2031-maturing dollar bonds climbed from a low of 6.7% in January to 8.2% earlier this month. Recently, leaders of some of the world's largest AI platforms, including OpenAI, have called for slowing AI progress over safety concerns, adding another layer of uncertainty. This factor has driven the cost of insuring SoftBank's debt against default to a three-year high recently.
OpenAI CEO Sam Altman's comments that the company will not go public this year have been closely watched by investors; an IPO would have increased the liquidity of SoftBank's holdings. Both S&P Global Ratings and Fitch Ratings assign SoftBank a BB+ rating, the highest speculative-grade rating at each agency. By comparison, Alphabet and Amazon, this year's two largest corporate bond issuers for 2026, hold AA+ and AA ratings respectively, both above Japan's sovereign rating.
From the Alibaba Legend to OpenAI: Betting on the Next Generation of Global 'Super Platforms'
SoftBank's large-scale AI financing continues to attract considerable bond investment demand, but investors are also demanding higher returns on their capital. The planned $10 billion and 1 billion euro bond issuance has drawn over $20 billion in preliminary subscription interest; the longest 7.5-year dollar tranche explored a yield around 10%, while the longest 6-year euro tranche was quoted at around 8.5%. The latest subscription enthusiasm thus indicates that global credit capital remains willing to participate in SoftBank's AI expansion, though the $20 billion currently represents non-binding intent, and the approximately 10% is not yet the final issuance yield.
If the transaction completes successfully, it will further broaden SoftBank's medium- to long-term financing channels, providing funding support to fulfill ongoing OpenAI investment commitments. Son's aggressive borrowing and pledging of Arm shares reflects a clear capital allocation logic: leveraging existing assets to secure financing and completing investments during a critical phase of AI platform and computing resource expansion.
SoftBank's July announcement indicated plans to invest an additional $10 billion into OpenAI on October 1; in September, it announced early repayment of the $25.9 billion outstanding balance under the bridge loan. Current financing thus simultaneously involves subsequent capital contributions and financing structure adjustments. Equity pledges allow obtaining funds while retaining shareholding, while bonds help extend financing maturities.
Viewed from the perspective of the global AI data center construction boom, power connections, campus development, chip procurement, and cluster deployment all require upfront investment; securing funding in a timely manner helps translate long-term AI demand assessments into actual delivery capacity.
In 2000, Son first invested approximately $20 million in Alibaba, and through long-term holdings, shared in the record-breaking value growth of the Chinese e-commerce platform as it moved from huge early-stage losses to the global capital markets spotlight — an investment legend. Today, Son believes OpenAI, which he is heavily funding, holds similarly unmatched growth potential as a mass-scale user gateway and enterprise technology platform — namely betting that cutting-edge AI large-model capabilities, developer ecosystems, paid services, and enterprise workflows reinforce each other, with commercialization space expanding comprehensively as application scope grows.
This time, Son also seeks to enhance investment synergies through industrial positioning — identifying platforms that may expand commercial boundaries over the long term and building continuous supply capacity around them: OpenAI's development generates model and application demand, computing infrastructure absorbs that demand, and chip and enterprise service businesses capture commercial opportunities within that chain.
Son has emphasized more than once this year that he pursues multi-layered value creation through "core platform equity appreciation plus computing service revenue plus industrial chain business growth." SoftBank stated explicitly in its investment announcement that the additional investment supports both OpenAI's research and ecosystem expansion and advances its own ASI strategy.
The AI super platform SoftBank is building is no longer a single-point bet but an increasingly complete "ASI integrated stack": at the base lies the Arm architecture and Arm's self-developed data center CPUs; in the middle sits British AI chip design company Graphcore Ltd., fully acquired by SoftBank Group, along with Ampere, recently officially acquired; at the top are OpenAI, Stargate (the "Star Gate"), and enterprise-grade cloud AI computing platform positioning alongside Oracle — plus SB Neo, a new neocloud venture. Son himself has publicly stated that SoftBank aims to become the largest-scale AI computing and application foundational platform provider in the "Super Artificial Intelligence" (ASI) era over the next decade, adopting an almost "all-in" aggressive investment posture toward OpenAI, the developer of ChatGPT and global leader in AI large models. Oracle serves primarily as Stargate's cloud and infrastructure partner, while SoftBank's enterprise-facing joint platform is SB OpenAI Japan, established together with OpenAI.