A $10 billion payment can close an investment commitment and still leave investors asking what it will ultimately buy. SoftBank says it has completed its final installment to OpenAI, bringing its total investment in the company to $64.6 billion.
What the final payment closes
The last installment: SoftBank transferred $10 billion on October 1, completing a three-part, $30 billion commitment made as part of a funding round in February. Its stake in OpenAI is estimated at 13%.
The round was reported to have raised between $110 billion and $122 billion, with OpenAI valued at about $730 billion before the investment. That would put its post-investment valuation between $840 billion and $852 billion.
SoftBank and Nvidia each committed $30 billion. Amazon committed $50 billion, with part of its investment tied to milestones.
How SoftBank funded the payment
Borrowing played a part: To finance the final installment, SoftBank issued dollar- and euro-denominated bonds worth about $11 billion combined.
The investment makes SoftBank one of OpenAI's largest backers and ties a significant share of its capital to a single private AI company. The scale of the commitment also reflects the substantial funding sought for AI models and data centers, though the investment itself does not settle how those costs will produce commercial returns.
The unresolved questions
SoftBank shares fell on the Tokyo exchange after the announcement. Investors were concerned about the financial burden of the company's aggressive AI investments.
The open question is whether the spending will secure lasting access to infrastructure and lead to products with measurable commercial value. For now, the payment closes a financing obligation. It does not close the debate over what the investment will deliver.