How exposed is SoftBank to OpenAI?
Very. SoftBank has invested $64.6 billion in OpenAI for a stake of about 13 percent, mostly using debt and asset sales rather than operating profits. S&P estimates OpenAI is about 30 percent of SoftBank's investment assets, and its $45 billion gain on the stake is still on paper.
Balance-sheet figures are as of June 30, 2026, the latest in our record. Investment figures run to October 1, 2026. Data as of 2026-11-05.
How the OpenAI stake was paid for
| Source of money | Amount | Source |
|---|---|---|
| Bridge loan signed March 2026 (limit $40B, $10B cancelled undrawn; repaid in September) | $30B drawn | SoftBank Group, 2026-09-09 Reuters via The Star, 2026-10-01 |
| Bonds, September 2026 (including record $11.1B junk bond sale) | $17.4B | Bloomberg/Reuters via The Star, 2026-09-24 |
| Syndicated bank loan, September 2026 | $11.87B | European Business Magazine, 2026-09-25 |
| Loan secured on its OpenAI shares, arranged August 2026 | About $10B | Reuters via The Star, 2026-08-06 |
| Loan secured on its Arm shares | About $20B | Reuters via The Star, 2026-08-04 |
| Sales of Nvidia and T-Mobile US shares, 2025 | About $15B | The Nightly (CNBC report), 2025-11-12 |
These are the main funding sources, not a tally that sums to $64.6B. Bonds and the bank loan helped repay the bridge loan, and some money served other purposes.
What the stake is worth
SoftBank's total investment is $64.6 billion, for about 13 percent of OpenAI. Reuters via The Star, 2026-10-01 At the $852 billion valuation of OpenAI's March round, 13 percent is about $111 billion (our arithmetic). SiliconANGLE, 2026-03-31 SoftBank's cumulative gain of $45 billion is unrealized, and it booked no OpenAI gain in April to June 2026. Reuters via The Star, 2026-08-06 The IPO proceeds it expected from OpenAI and SB Energy have been delayed. Bloomberg/Reuters via The Star, 2026-09-24
How much of SoftBank rests on it
S&P estimates OpenAI at about 30 percent of investment assets, and CreditSights puts Arm and OpenAI together at about three-quarters of group asset value. European Business Magazine, 2026-09-25 Bloomberg/Reuters via The Star, 2026-09-24
The debt measures disagree. SoftBank reports a loan-to-value ratio of 13.0 percent at June 30, 2026, against its own ceiling of 25 percent. SoftBank Group, 2026-08-06 S&P's version, which treats margin loans differently, was about 33 percent at the end of March, when SoftBank's own figure was 17 percent. Reuters via The Star, 2026-08-04
What lenders are saying
SoftBank's dollar notes in September carried coupons of 8.625 to 9.75 percent, and the yearly cost of insuring its debt rose above 4 percent from about 2.8 percent in June. S&P rates it BB+, below investment grade. Bloomberg/Reuters via The Star, 2026-09-24 European Business Magazine, 2026-09-25
Our read
This section is our judgment, kept separate from the sourced record above.
SoftBank's risk is that OpenAI's value holds up only as long as new money keeps arriving, and that SoftBank's capacity to borrow depends on that same value. At half the March valuation, the stake would be worth about $55 billion, below what SoftBank paid (our arithmetic).
The $10 billion loan secured on OpenAI shares is the clearest loop: the same asset secures the debt and is what the debt helped buy.
What would change this answer
- The valuation of OpenAI's current round ($1.25 trillion target, cut from $1.4 trillion)
- SoftBank's next reported loan-to-value ratio
- The cost of insuring its debt
- Timing of an OpenAI or SB Energy IPO