SoftBank Group shares climbed more than 7% in Tokyo on Thursday as the Japanese technology investor returned from a three-day market holiday and confirmed an $11.1 billion bond issuance to complete its massive follow-on investment in OpenAI.

The rally came after SoftBank (OTC:SFTBY) priced a combination of dollar- and euro-denominated senior notes, with the bulk of the proceeds earmarked for the final $10 billion tranche of a $30 billion commitment made in February. The payment is expected to close on October 1.

The company said the offering consists of $10 billion in dollar-denominated notes split across three maturities: $1 billion due in 3.5 years at 8.625%, $4.5 billion due in 5.5 years at 9.25%, and $4.5 billion due in 7.5 years at 9.75%. On the euro side, SoftBank priced two €500 million tranches with four- and six-year tenors carrying yields of 7.125% and 8%, respectively.

All five tranches are unsecured and unguaranteed, with BB+ ratings from S&P Global Ratings Japan and Fitch Ratings Japan. The notes will be listed on the Singapore Exchange and marketed primarily to investors in the United States, Europe, and Asia, excluding Japan’s domestic market. Settlement is scheduled for September 29.

Once the final tranche closes, SoftBank’s cumulative investment in the ChatGPT maker will reach $64.6 billion, giving the conglomerate an approximately 13% stake. That ownership position, however, may not carry conventional governance rights after OpenAI retained control under its nonprofit structure while scaling back a planned transition to full for-profit status.

The financing push underscores the scale of Chief Executive Masayoshi Son’s bet on artificial intelligence. Beyond OpenAI, SoftBank has been pursuing an array of AI-related initiatives, including Stargate-linked data centers, U.S. AI infrastructure, expansion of Arm Holdings (NASDAQ:ARM), and its planned acquisition of ABB Robotics (OTC:ABBNY).

Financing Structure and Terms

The bond sale represents one of the largest corporate debt offerings SoftBank has executed in recent years. The interest rates, ranging from 7.125% on the shortest euro tranche to 9.75% on the longest dollar tranche, reflect the high-yield nature of the issuer and investor appetite for exposure to the AI sector.

CurrencyAmountMaturityCoupon/YieldUSD$1 billion2030 (3.5 years)8.625%USD$4.5 billion2032 (5.5 years)9.25%USD$4.5 billion2034 (7.5 years)9.75%EUR€500 million2030 (4 years)7.125%EUR€500 million2032 (6 years)8.00%

Note: All tranches are senior unsecured notes rated BB+ by S&P Global Ratings Japan and Fitch Ratings Japan. Settlement is scheduled for September 29, 2026, with listing on the Singapore Exchange.

In conjunction with the bond issuance, SoftBank also disclosed plans to terminate the remaining $10 billion borrowing facility under a $40 billion bridge loan agreement signed in March. The company is replacing short-term bridge financing with longer-dated bond maturities, extending its debt profile while locking in fixed-rate funding.

Broader Financing Efforts

The bond sale follows reports that Apollo Global Management (NYSE:APO) is in discussions to increase its loan to SoftBank’s Vision Fund II from $5.4 billion to as much as $9 billion. Apollo previously provided financing extensions to the venture capital arm in 2021.

During SoftBank’s fourth-quarter earnings call, an executive indicated the company could use its OpenAI holdings as collateral for additional financing, including through a margin loan. Earlier this month, SoftBank also issued ¥1 trillion ($6.3 billion) in corporate bonds targeted at retail investors in Japan.

The aggressive fundraising comes amid heightened scrutiny of SoftBank’s balance sheet. Investors have increasingly questioned how the conglomerate will finance its sprawling AI ambitions and what rising leverage means for its credit profile. The BB+ ratings on the new notes place them in speculative-grade territory, consistent with SoftBank’s existing corporate ratings.

Market Reaction and Strategic Context

The 7% share surge on Thursday suggests investors view the completed financing as a positive signal, removing uncertainty around how SoftBank would fund the final OpenAI tranche. The stock had been under pressure in recent months as questions mounted about the sustainability of the company’s AI spending.

SoftBank’s relationship with OpenAI has deepened significantly since the initial investment. The $30 billion follow-on commitment, announced in February, was structured in three tranches, with the first two already completed. The third tranche, now funded by this bond sale, will finalize the transaction.

The investment positions SoftBank as one of OpenAI’s largest shareholders, though the governance structure remains unusual. OpenAI’s nonprofit parent retains control, and the company has scaled back plans to fully convert to a for-profit entity, meaning SoftBank’s 13% stake may not translate into proportional board representation or voting power.

For Son, the OpenAI investment is central to a broader strategy of positioning SoftBank at the center of the AI ecosystem. The company has committed nearly $65 billion to OpenAI alone, while simultaneously investing in the infrastructure layer through data centers, the semiconductor layer through Arm, and the robotics layer through the pending ABB Robotics acquisition.

The bond market’s willingness to absorb $11.1 billion in SoftBank debt at rates between 7% and 10% indicates continued investor appetite for AI-related exposure, even as questions persist about valuation and long-term returns. The successful pricing also demonstrates that SoftBank retains access to capital markets despite its leveraged balance sheet.

Looking ahead, the completion of the OpenAI investment removes a significant near-term funding overhang. Attention will now shift to execution across SoftBank’s other AI initiatives, particularly the Stargate data center project and the integration of ABB Robotics, both of which will require substantial additional capital in the coming years.