Leaked OpenAI Cap Table Reveals Microsoft’s 17x Windfall While CEO Sam Altman Holds Zero Equity

Key Takeaways

• Microsoft’s approximately $13B investment in OpenAI now values at roughly $228B — delivering a 17x return
• SoftBank deployed $64.6B and sits on over $50B in gains, with holdings valued at approximately $99.3B
• OpenAI CEO Sam Altman maintains no ownership stake in the AI powerhouse
• The original OpenAI Foundation retains 25.8% ownership with zero capital outlay — while maintaining complete board control
• Nvidia currently shows paper losses, holding a $30.1B cost basis against $29.6B in current valuation

A confidential capitalization table detailing OpenAI’s ownership structure emerged online in early April, sparking widespread discussion about who benefits from the company’s meteoric rise. Investor Sheel Mohnot shared the document on X, which appears compiled from publicly available filings and secondary market transactions. The data suggests OpenAI’s post-money valuation stands at $852 billion after completing a $122 billion financing round.

The leaked document provides granular details on ownership percentages, capital invested, and profit multiples for each significant backer. This represents the most comprehensive public view to date of the financial landscape awaiting OpenAI’s anticipated public offering.

Microsoft emerges as the dominant winner based on the figures. The tech giant deployed roughly $13 billion through multiple investment rounds — beginning with a $1 billion commitment in 2019, followed by a substantial $10 billion injection in January 2023, plus an additional $2 billion in 2024. The resulting 26.79% ownership position now carries an estimated value of $228.3 billion, representing approximately 17.6x returns. No comparable investor has achieved similar multiples at this magnitude.

Microsoft’s quarterly 10-Q regulatory filings substantiate the $13 billion total investment amount. OpenAI recently identified Microsoft as a material business dependency in investor documentation, referencing revenue-sharing agreements and exclusive cloud computing arrangements.

SoftBank has deployed $64.6 billion into OpenAI, establishing itself as the largest individual capital provider besides Microsoft. The investment firm’s 11.66% ownership translates to current valuations around $99.3 billion. This positions SoftBank with unrealized gains exceeding $50 billion. CNBC reported that SoftBank completed its $40 billion funding obligation by December 2025, utilizing a $40 billion bridge facility from JPMorgan and Goldman Sachs.

Pioneer Investors Secured Exceptional Returns

Early-stage backers captured the most impressive return multiples, despite smaller absolute gains. Khosla Ventures contributed approximately $50 million during 2019, with that position now valued near $1.5 billion — roughly 30x returns. Sound Ventures, the investment vehicle co-created by entertainer Ashton Kutcher, deployed between $20-30 million and currently holds approximately $1.3 billion in value, reflecting a 43x multiple. Thrive Capital’s $3.5 billion commitment secured a 1.98% stake currently worth $16.9 billion.

Nvidia stands as the singular investor showing negative returns. The chipmaker controls 3.47% of OpenAI, presently valued at $29.6 billion, measured against a $30.1 billion cost basis. Nvidia’s investment structure included substantial GPU computing credits alongside cash, creating complexity in precise return calculations.

Altman’s Equity Remains Undetermined

Among the most noteworthy revelations in the ownership table is that Sam Altman, who has served as OpenAI CEO since 2019, possesses zero equity ownership. His stake appears marked as undetermined. OpenAI’s board chairman Bret Taylor stated in October 2024 that concrete equity allocations remained unfinalized. Altman personally refuted speculation about imminent equity grants during an internal company meeting.

The OpenAI Foundation, the original nonprofit entity, maintains 25.8% ownership without any capital investment — creating a theoretically infinite return multiple on approximately $219.8 billion in estimated value. While representing a minority economic interest, the Foundation retains exclusive authority over all board member appointments.

OpenAI reportedly targets a public market debut during 2026 or early 2027, potentially at a $1 trillion valuation milestone. Industry observers widely anticipate that listing event will definitively establish Altman’s equity compensation.