OpenAI Cap Table Leaked: Microsoft Turned $13B Into $228B — Sam Altman Owns Zero

The cap table for the most valuable private company in history just leaked. At an $852 billion post-money valuation, here is who made what — and why the most shocking number in the entire document belongs to the man who has run the company since 2019.

Sam Altman owns zero equity in OpenAI.

Not a rounding error. Not a small stake. Zero. The CEO of an $852 billion company that he built from a nonprofit research lab into the defining AI company of the decade currently holds no shares. His equity grant is listed as "TBD/Pending" — contingent on the completion of OpenAI's conversion from nonprofit to Public Benefit Corporation. Until that conversion closes, Altman has been running the most consequential technology company in the world for free.

Everyone else at the table has made generational wealth. Some made historic wealth. The gap between what OpenAI's investors have earned and what its CEO has earned is the most extraordinary governance story in Silicon Valley history.

The Numbers: Who Owns What at $852 Billion

The document that leaked — first published by Forbes and rapidly shared across financial and tech media — reconstructs OpenAI's ownership structure based on public filings, disclosed investment rounds, and analyst estimates. Cost-basis figures are best estimates. The ownership percentages are consistent with what has been reported across multiple sources.

Microsoft: $13 billion invested → $228.3 billion current value

Microsoft owns 26.79% of OpenAI. At the $852 billion valuation, that stake is worth $228.3 billion. Microsoft's total investment across multiple tranches is approximately $13 billion. That is a return of 1,656% — or roughly 17.6x in less than four years. The $215 billion unrealized gain is larger than the entire market cap of most Fortune 500 companies. It is the single greatest technology investment in corporate history by absolute dollar return.

OpenAI Foundation (the original nonprofit): $0 invested → $219.8 billion

The foundation that Altman, Elon Musk, Greg Brockman, and others created in 2015 holds 25.80% of the PBC at a zero cost basis. That is an infinite return multiple on $219.8 billion in estimated value. The foundation was the legal entity that owned OpenAI before the for-profit restructuring. This is the equity that is supposed to eventually fund Altman's long-stated mission of ensuring artificial general intelligence benefits humanity. Whether a nonprofit holding company stake in a $852 billion for-profit entity actually does that is a question worth asking.

SoftBank: ~$14 billion invested → $64+ billion current value

SoftBank holds 11.66% of OpenAI after completing its $41 billion investment in early 2026, bringing total committed capital to approximately $64.6 billion. The paper gain on earlier tranches — invested at much lower valuations — is estimated at $50 billion. Masayoshi Son has transformed the Vision Fund's AI thesis from a punchline (WeWork, Uber losses) into its defining vindication. SoftBank owns more of OpenAI than any entity except Microsoft and the foundation itself.

Amazon: ~$15 billion invested → ~$39.7 billion current value

Amazon holds 4.66% of OpenAI, primarily through its $15 billion Series C Preferred investment from late 2024. The conversion terms on that preferred stake matter enormously — how it converts in an IPO scenario determines whether Amazon's return is extraordinary or merely very good. AWS is simultaneously OpenAI's largest infrastructure provider and one of its largest investors. That dual relationship gives Amazon leverage that does not show up in equity percentages.

NVIDIA: disclosed investment → ~$29.6 billion current value

NVIDIA holds approximately 3.47% of OpenAI. For a company that supplies the hardware OpenAI runs on, having equity in the largest consumer of that hardware is a structural hedge. NVIDIA's return is exceptional in percentage terms. It is also somewhat circular — the more successful OpenAI is, the more H100s and H200s it buys, the more NVIDIA's chip revenue grows, the higher NVIDIA's stock goes.

Thrive Capital: ~$3.5 billion invested → $16.9 billion current value

Josh Kushner's Thrive Capital holds 1.98% of OpenAI. A 4.8x multiple on $3.5 billion is $13.4 billion in profit. Thrive was the lead investor in OpenAI's $6.6 billion Series B in late 2024, getting in at what looked like a high price and looks prescient in retrospect.

Khosla Ventures: ~$50 million invested → ~$1.5 billion

Vinod Khosla was one of OpenAI's original backers. A $50 million early bet returning $1.5 billion is a 30x multiple. This is what early-stage venture is supposed to look like — small checks at pre-product stage that return extraordinary multiples when the company succeeds.

Sound Ventures (Ashton Kutcher): ~$30 million invested → ~$1.3 billion

The most memed entry on the cap table. Ashton Kutcher and Guy Oseary's Sound Ventures invested approximately $30 million in early OpenAI rounds. At current valuation that stake is worth roughly $1.3 billion — a 43x multiple. Kutcher will have made more money from OpenAI than most professional venture capitalists who passed on it.

Andreessen Horowitz: Small early position, strong percentage multiple, modest absolute return. a16z was an early OpenAI supporter but did not deploy significant capital at scale into later rounds. The percentage return is excellent. The dollar return reflects the position size.

The Strategic Block That Controls OpenAI

Microsoft, SoftBank, Amazon, and NVIDIA collectively own 46.58% of OpenAI. Add the foundation's 25.8% and the top five entities control 72.38% of the company. This is not a startup with distributed ownership. This is a company effectively controlled by four of the world's largest technology corporations plus a nonprofit that exists to ensure AI benefits humanity — and that will likely be reshaped significantly when the PBC conversion completes.

The Microsoft relationship deserves particular scrutiny. Microsoft is simultaneously OpenAI's largest shareholder, its largest cloud infrastructure provider (Azure hosts OpenAI's compute), and its largest enterprise distribution partner (Copilot, which runs on GPT-4 and GPT-5 series models, is Microsoft's fastest-growing product). The three roles are mutually reinforcing in good times. In bad times — a competitor undercutting on price, a model capability gap, a regulatory action — the concentration creates conflicts that a 26.79% equity stake makes very difficult to resolve independently.

Why Sam Altman Owning Nothing Is the Real Story

Every other senior leader of a major technology company owns equity in their company. Jensen Huang owns roughly 3.5% of NVIDIA — worth approximately $60 billion. Mark Zuckerberg controls Meta through dual-class shares. Sundar Pichai, Andy Jassy, Satya Nadella — all own substantial equity stakes. It is the foundational assumption of Silicon Valley that equity alignment between CEO and company is how you ensure that the person running the company is motivated to maximize its value.

Sam Altman has been running OpenAI since 2019. He oversaw the development of GPT-3, GPT-4, ChatGPT's launch that put AI in front of 100 million users in two months, the $122 billion fundraising round, and the transformation of a nonprofit into an $852 billion for-profit entity. He survived a board coup in November 2023 that fired him and saw him reinstated within days. Through all of this, he has held zero equity.

The stated reason is OpenAI's nonprofit origins. When the company was founded, Altman took no equity as part of the charitable structure — the company was not supposed to be a profit-maximizing entity. The for-profit subsidiary structure, the PBC conversion, and the massive fundraising rounds have progressively eroded that original structure, but the equity grant to Altman has remained contingent on the conversion completing.

What Altman will receive when the PBC conversion closes has not been officially disclosed. Reports suggest he is negotiating for approximately 7% of the PBC — which at $852 billion would be worth roughly $59.6 billion, making him one of the wealthiest people in the world overnight. The negotiation is reportedly contentious. The nonprofit board has obligations to ensure the charitable mission is protected in the conversion, and a $59 billion grant to the CEO is exactly the kind of transaction that draws scrutiny from state attorneys general and the IRS.

What This Means for the IPO

OpenAI is on a stated path to IPO — SoftBank's structure requires it, the $122 billion round was partly structured around it, and Altman has discussed it publicly. The cap table leak matters for the IPO in several ways.

Public market investors will price the company against these ownership stakes. Microsoft at 26.79% holding a position worth $228 billion on their books means any IPO valuation below that creates a paper loss for Microsoft's balance sheet — creating pressure for a high IPO price that may not reflect operating fundamentals. OpenAI is burning cash at an extraordinary rate: the company pays Microsoft hundreds of millions in Azure fees quarterly, and its revenue, while growing fast, has not reached profitability.

The nonprofit foundation's 25.8% stake also creates a unique dynamic. A nonprofit entity holding a quarter of a public company worth $852 billion has governance implications that no investment banker has navigated before. The IRS and California Attorney General have ongoing oversight of the conversion. Public shareholders buying into an IPO will be buying into a company where a nonprofit entity with charitable obligations controls a quarter of the equity and the conversion terms are still being negotiated.

The Uncomfortable Comparison

OpenAI was founded as a nonprofit explicitly to prevent the concentration of transformative AI technology in the hands of a few powerful entities. The leaked cap table shows that Microsoft, one of the world's largest corporations, has turned a $13 billion investment into $228 billion — the largest corporate investment return in modern history — by being the primary funder and infrastructure provider for the company that was supposed to prevent exactly this kind of concentration.

Elon Musk, who co-founded OpenAI and left citing concerns about its for-profit direction, has a lawsuit claiming the original charitable mission has been abandoned. The cap table does not settle that argument. But it provides the most concrete evidence yet of how the financial structure of the company has evolved from its stated founding principles.

Whether that matters — whether the mission language of the original nonprofit was ever more than aspirational — is a question developers and technologists who rely on OpenAI's APIs need to think about. The company that trained GPT-4 on the internet's data and charges $20/month for access is now a structure that has made Microsoft $215 billion richer while its CEO owns nothing and the nonprofit board negotiates over billions in equity grants.

For the current API pricing across OpenAI and competitors, the LLM API Pricing Tracker has live rates. For how OpenAI's $122 billion funding round was structured, see the OpenAI $122B funding analysis.

Key Takeaways

• Microsoft: $13B invested → $228.3B current value — 1,656% return, the largest corporate investment gain in modern tech history
• Sam Altman: runs an $852B company and owns zero equity — grant pending PBC conversion, reportedly negotiating ~7% ($59.6B)
• OpenAI Foundation (nonprofit): $0 cost basis → $219.8B value — infinite return multiple on 25.8% stake
• SoftBank: 11.66% stake, ~$50B paper gain — Masayoshi Son's AI thesis vindicated after Vision Fund losses
• Amazon: 4.66% stake from $15B Series C — simultaneously the company's largest cloud provider and major shareholder
• NVIDIA: 3.47% stake — structurally circular: more OpenAI success = more GPU revenue = higher NVIDIA stock
• Ashton Kutcher: ~$30M → ~$1.3B — 43x multiple, most memed VC return of the decade
• Microsoft + SoftBank + Amazon + NVIDIA own 46.58% collectively — four corporations control nearly half of the company meant to prevent AI concentration
• IPO complexity: nonprofit entity holding 25.8% of a public company is unprecedented; IRS and California AG oversight ongoing