All-In, Fully Funded: SoftBank Completes Its $64.6 Billion OpenAI Wager at 13%

Early in October, one of the defining financial engineering exercises of the AI era quietly reached its endpoint. SoftBank Group confirmed it had executed the final $10 billion tranche of its $30 billion follow-on investment in OpenAI, bringing its cumulative commitment to $64.6 billion and its ownership interest in the ChatGPT maker to approximately 13%. With that wire transfer, Masayoshi Son’s “all-in” wager on artificial intelligence is no longer a promise on a slide — it is a fully funded, closed position, and one of the largest single-company bets in the history of organized capital markets.

The completion is notable less for the number than for what it closes out. SoftBank’s follow-on was announced in February as part of OpenAI’s $110 billion raise at a $730 billion pre-money valuation — a round that also pulled in $30 billion from NVIDIA and $50 billion from a syndicate of other investors. At the time, SoftBank said its cumulative investment would total $64.6 billion for roughly 13% of the company. The final tranche lands that plan exactly on target, with no slippage and no renegotiation, something that could not be said for several other mega-round financing pledges across the industry this year.

What actually happened

According to Reuters and SoftBank’s own disclosures, the mechanics break down into three pieces:

• The final $10 billion tranche executed. This closes the $30 billion follow-on announced in February 2026, on top of the $34.6 billion SoftBank had already invested across earlier rounds.
• The bridge facility is dead. SoftBank canceled the remaining $10 billion of undrawn capacity under its $40 billion bridge facility, effective September 30. The company had already repaid the entire outstanding balance of $25.9 billion on September 15, ahead of schedule, according to Bloomberg.
• Cumulative position: $64.6 billion for ~13%. That makes SoftBank the largest outside shareholder in OpenAI by a wide margin, and makes the OpenAI stake by far the biggest single holding in the SoftBank portfolio — bigger, at cost, than its storied Alibaba position was at its peak.

The market’s verdict on the completion was, characteristically, sour. SoftBank shares slid as much as 5.6% in Tokyo after the announcement, extending a rough stretch for the stock. Investors have spent months marking Son’s AI positions against a backdrop of Anthropic and OpenAI themselves calling for slower development, an OpenAI IPO that Sam Altman publicly ruled out for 2026, and mounting scrutiny of how the whole edifice is financed. Completing the bet did not resolve that anxiety — it concentrated it.

The financing stack behind the wire

To understand why this matters, it helps to look at how the $64.6 billion was actually raised. SoftBank did not write the check out of cash reserves. The position was assembled through an aggressive stack of instruments:

1. A $40 billion bridge loan syndicated across 21 lenders, used to fund early tranches — then repaid in full ($25.9 billion outstanding) on September 15.
2. Around $15 billion of note issuance in 2026, including an $11 billion junk-bond sale in September that was explicitly marketed as funding the OpenAI bet.
3. A $10 billion loan secured against the OpenAI stake itself, reported by the Wall Street Journal — a structure that, notably, requires SoftBank to inject additional cash under certain conditions.

Layered on top are the industry-level circularities: NVIDIA invested $30 billion into OpenAI in the same round, and OpenAI in turn has committed hundreds of billions to NVIDIA and other compute suppliers over the coming decade. Broadcom has agreed to lend Anthropic up to $42 billion to finance infrastructure. Money in the AI economy increasingly arrives pre-owed.

Why the 13% number matters

SoftBank’s 13% stake makes it the entity with the most to lose — and the most to gain — from OpenAI’s eventual path to public markets. Altman has said OpenAI will not go public in 2026, which removes the cleanest mark on SoftBank’s position for now. In the meantime, the stake’s paper value floats on secondary transactions and round pricing: OpenAI’s February raise implied a $730 billion pre-money valuation, and subsequent reports have suggested private marks have climbed higher since.

For Son, the completion is the vindication of a bet he has framed in civilizational terms. SoftBank’s earlier ventures into this cycle — the Vision Fund’s late-stage excesses, the WeWork implosion — taught the market to discount his enthusiasm. The OpenAI position is different in kind: it is concentrated, unlevered at the subsidiary level, and now fully paid for. Whether it is different in outcome depends entirely on OpenAI’s revenue trajectory, which by latest reports has crossed an annualized run rate above $65 billion, and on whether the compute commitments the company has signed can be serviced without another era-defining raise.

What to watch next

• The November midterms window. Reuters reports Anthropic is targeting a mid-November IPO at up to a $2 trillion valuation. A successful listing would reset public benchmarks for every private AI mark, SoftBank’s included.
• SoftBank’s own balance sheet. With the bridge repaid and the bonds sold, the next question is whether Son pivots to monetization — partial stake sales, collateralized structures — or doubles down on the Stargate-adjacent infrastructure buildout.
• Cross-holdings as systemic risk. When a single investor owns 13% of the leading lab, has borrowed against that stake, and sits inside a web of reciprocal compute commitments, the failure modes stop being idiosyncratic. Regulators have begun asking about exactly this.

The AI boom has produced plenty of large numbers. What it has produced less of is closure. SoftBank’s completed $64.6 billion position is one of the few fully-executed facts in the cycle — a bet placed, financed, and closed. Now it just has to pay off.