SoftBank Group stock falls 3.18 percent as AI debt draws scrutiny

Published on 09/25/2026 at 16:39 | Editorial responsibility: Rafael Müller, Editor-in-Chief AD HOC NEWS

SoftBank Group issued USD 11.1 billion of bonds on September 24, 2026, to support its OpenAI investment. The Tokyo listing carried JPY 35,048,380,761,150 in market value on September 25.

SoftBank Group, JP3436100006, Illustration mit AI erstellt.

SoftBank Group stock (ISIN JP3436100006) fell 3.18 percent to JPY 6,150 on the Tokyo Stock Exchange on September 25, 2026, as investors assessed the financing burden behind its artificial intelligence strategy. The move followed the company's USD 11.1 billion bond issue announced on September 24, 2026.

Bond issue funds OpenAI payment

According to SoftBank Group in its September 24, 2026 release, the notes comprise USD 10 billion of dollar-denominated debt and EUR 1 billion of euro-denominated debt, equivalent to USD 11.1 billion.

The proceeds include the USD 10 billion payment for the third and final tranche of SoftBank Group's USD 30 billion follow-on investment in OpenAI, expected to close on October 1, 2026. The release also says SoftBank Group expects to cancel the remaining USD 10 billion of undrawn capacity under a USD 40 billion bridge facility.

Debt costs sharpen the risk picture

Reuters reported on September 24, 2026, that the dollar notes carry interest rates of 8.625 percent, 9.25 percent and 9.75 percent, while the euro notes yield 7.125 percent and 8 percent. The spread between the lowest and highest stated rate is 0.875 percentage points.

Reuters also reported that SoftBank's five-year credit default swap spread exceeded 400 basis points during the week, compared with 280 basis points in June. That comparison gives the share-price decline a clear financing angle: the OpenAI strategy is expanding alongside a more expensive debt stack.

Stock stays below yearly high

SoftBank Group's market capitalization was JPY 35,048,380,761,150 on September 25, 2026, with trading volume of 62,333,000 shares. The stock's JPY 3,365 to JPY 9,074 52-week range places the JPY 6,150 price 32.22 percent below the yearly high.

The company's investor-relations calendar lists Q1 FY2026 earnings results and the earnings investor briefing on August 6, 2026, while the September 24 bond announcement is the latest financing milestone. For investors, the central calculation is the balance between AI asset exposure and the interest cost required to fund it.

JPY 6,150 marks the latest level

SoftBank Group stock stood at JPY 6,150 on the Tokyo Stock Exchange on September 25, 2026, down JPY 202 from the prior close. The session range was JPY 6,040 to JPY 6,242.