OpenAI, the company behind ChatGPT, DALL-E, and the GPT model family, closed a staggering $110 billion funding round in February 2026 — the largest private tech fundraise in history — at an $840 billion post-money valuation. With an IPO targeted for the second half of 2026 and a potential trillion-dollar-plus listing price, investor interest has never been higher.

The short answer for public market investors: MSFT, SFTBY (9984.T), AMZN, and NVDA all hold massive stakes. But the full picture involves a Byzantine corporate restructuring, a CEO who owns zero equity, capped early-investor returns, and a web of strategic cloud commitments worth hundreds of billions.

In this article, we reconstruct OpenAI's ownership structure from SEC filings, press releases, and investor disclosures, then map every route — public equities, ETFs, secondary markets, and private fund access — to gain exposure before the IPO.

Also in this series: How to Invest in Anthropic

OpenAI's Funding History: From Non-Profit to $840B Valuation

OpenAI's journey is unlike any other tech company. Founded as a non-profit in 2015 with $1 billion in pledged donations from Elon Musk, Sam Altman, Peter Thiel, Reid Hoffman, and others, it transitioned to a "capped-profit" structure in 2019, and then restructured into a public benefit corporation (PBC) in October 2025. This history matters because it directly shapes who owns what — and what their returns are capped at.

Round Date Amount Raised Valuation Lead Investor(s)
Non-Profit Founding Dec 2015 $1B pledged N/A Musk, Altman, Thiel, Hoffman, AWS
Seed (Capped-Profit) 2019 ~$130M ~$1B Khosla Ventures, Reid Hoffman Foundation
Microsoft Strategic I Jul 2019 $1B — Microsoft
Microsoft Strategic II Jan 2023 $10B ~$29B Microsoft
Series A (Thrive-led) Apr 2023 $300M ~$27-29B Thrive Capital, Sequoia, a16z
Series E Oct 2024 $6.6B $157B Thrive Capital, SoftBank, Nvidia
Series F (SoftBank-led) Mar 2025 $40B $300B SoftBank ($30B), Microsoft, Coatue, Altimeter, Thrive
Secondary Sale Oct 2025 — $500B (implied) Various (secondary market)
PBC Restructuring Oct 2025 — ~$500B Microsoft receives 27% equity stake
Series G Feb 2026 $110B $840B (post-money) Amazon ($50B), SoftBank ($30B), Nvidia ($30B)

Total funding raised now exceeds $168 billion across 11 rounds from 67 investors. Revenue is reportedly approaching $13 billion annualized as of early 2026, with 400+ million weekly active users on ChatGPT.

The October 2025 Restructuring: Who Owns What Now?

OpenAI's October 2025 restructuring from a capped-profit entity into a public benefit corporation (PBC) was the pivotal event for understanding today's cap table. The restructuring crystallized ownership into three buckets:

  • The OpenAI Foundation (non-profit): Retains approximately 26% of the for-profit OpenAI Group PBC, providing ongoing funding for the non-profit's safety-focused mission.
  • Microsoft: Received approximately 27% of the PBC on an as-converted, fully-diluted basis — making it the single largest external shareholder.
  • Employees, other investors, and new capital: The remaining ~47%, split among employees with vested equity, venture funds, and new strategic investors.

Critically, early investors from the 2019 seed round have their returns capped at 100x their investment. Later rounds have progressively lower caps. This means that even though OpenAI's valuation has skyrocketed, the earliest backers won't capture unlimited upside the way typical startup investors do.

Reconstructing the Cap Table: Major Shareholders

Microsoft (MSFT) — ~27% stake

Microsoft's position is the best-documented and the largest. The company has committed $13 billion in total funding (of which $11.6 billion was funded as of September 2025). Following the PBC restructuring, Microsoft disclosed a 27% stake valued at approximately $135 billion at the $500B valuation — and worth roughly $227 billion at the current $840B post-money valuation.

Microsoft's deal goes far beyond equity. It retains exclusive IP licensing rights and Azure API exclusivity through 2032, including access to any models that achieve AGI. OpenAI's products are deeply integrated into Microsoft's Copilot suite, Azure AI, and Bing. The cloud spending relationship alone is worth tens of billions — OpenAI has committed to spending $100 billion on AWS over eight years as part of its Amazon deal, but Azure remains the primary training and inference platform.

SoftBank (SFTBY / 9984.T) — ~13% stake

SoftBank has invested a cumulative $64.6 billion into OpenAI across two rounds: $30 billion led the Series F in March 2025, and another $30 billion in the February 2026 Series G (plus smaller earlier positions from the Series E). This makes SoftBank the second-largest shareholder with approximately 13% ownership.

Masayoshi Son has described OpenAI as the centerpiece of SoftBank's AI strategy. The firm is also a partner in Stargate, the joint venture between SoftBank, OpenAI, and Oracle to build massive AI data centers. SoftBank has sold stakes in other holdings, including some Nvidia shares, to fund its OpenAI commitment. At the $840B valuation, SoftBank's 13% is worth roughly $109 billion.

Amazon (AMZN) — up to ~6% stake (conditional)

Amazon committed up to $50 billion in the February 2026 Series G — the single largest check in the round. However, the deal is structured in phases: an initial $15 billion commitment, with the remaining $35 billion contingent on OpenAI completing an IPO or direct listing, or achieving AGI, before December 31, 2028.

At the $840B valuation, $50 billion would purchase roughly 6% ownership. Amazon also secured a strategic partnership: OpenAI will deploy 2 gigawatts of Amazon's Trainium AI chips and spend $100 billion on AWS over eight years. This deal is notable because Amazon is simultaneously Anthropic's largest cloud partner — it's hedging its AI bets across both frontier labs.

Nvidia (NVDA) — ~3.6% stake

Nvidia invested $30 billion in the February 2026 Series G, after smaller participation in the Series E. At the $840B post-money valuation, this translates to roughly 3.6% ownership worth about $30 billion. Nvidia CEO Jensen Huang suggested this may be Nvidia's last major direct investment in AI labs, calling the OpenAI stake potentially his "last big investment."

The strategic rationale is clear: OpenAI is one of the largest buyers of Nvidia GPUs on the planet. Securing a seat at the table ensures Nvidia remains the preferred silicon provider as OpenAI scales training and inference.

The OpenAI Foundation (Non-Profit) — ~26%

Following the restructuring, the non-profit foundation retains approximately 26% of the PBC. This stake funds OpenAI's ongoing safety research mission and is governed independently from the for-profit entity. The foundation received equity valued at more than $50 billion, making it one of the wealthiest non-profit endowments in the world.

Sam Altman — 0%

In one of the most unusual facts in tech, OpenAI's CEO owns zero equity in the company and earns a salary of just $76,001 per year. Altman has explained that he turned down equity to ensure the non-profit's board could remain "disinterested" and to demonstrate he could keep personal and professional incentives separate. He once held a fractional stake through a Y Combinator-affiliated VC fund but has since sold it.

This could change: reports in late 2024 suggested Altman might receive up to a 7% stake as part of the for-profit restructuring. As of the October 2025 announcement, however, no equity grant to Altman was disclosed.

Thrive Capital — Estimated 3-5%

Joshua Kushner's Thrive Capital has been one of OpenAI's most consistent investors, leading or co-leading the Series A, Series E, and Series F. Thrive also has a unique arrangement: OpenAI took a stake in Thrive Holdings, creating a circular investment relationship. Exact ownership percentages aren't public, but Thrive's cumulative position across multiple early rounds likely makes it the largest VC holder at an estimated 3-5%.

Early VC Investors — Collectively ~1-3%

Khosla Ventures, Reid Hoffman Foundation, Y Combinator, and Paul Buchheit (Gmail creator) were among the earliest investors in the 2019 seed round. Their collective stake is estimated at 1-3%, though returns are capped at 100x. At current valuations, these caps have almost certainly been hit, meaning additional upside accrues to later investors and the foundation.

Napkin Math: Estimated Ownership Breakdown

Shareholder Est. Stake % Est. Value ($840B) Public Ticker
Microsoft ~27% ~$227B MSFT
OpenAI Foundation ~26% ~$218B —
SoftBank ~13% ~$109B SFTBY / 9984.T
Amazon ~2-6% ~$17-50B AMZN
Nvidia ~3.6% ~$30B NVDA
Employees & option holders ~15-20% ~$126-168B —
Thrive Capital ~3-5% ~$25-42B —
Other VCs (Sequoia, a16z, Coatue, Tiger, etc.) ~5-8% ~$42-67B —
Early seed investors (Khosla, Hoffman, etc.) ~1-3% ~$8-25B (capped) —
Sam Altman (CEO) 0% $0 —

Note: These are estimates based on publicly available data. Amazon's stake is shown as a range because only $15B of its $50B commitment has closed, with the remainder conditional. Actual ownership may differ due to undisclosed terms, anti-dilution provisions, and employee option exercises.

Public Stock Exposure: The Investable Plays

Highest Intensity: SoftBank (SFTBY / 9984.T)

SoftBank is the most concentrated public bet on OpenAI. With a market cap of approximately $140 billion (as of early 2026) and an OpenAI position worth an estimated $109 billion, the OpenAI stake represents roughly 78% of SoftBank's entire market cap. SoftBank is essentially an OpenAI holding company at this point, with its Vision Fund portfolio and telecom assets as secondary businesses. Trading at such a deep implied discount to its OpenAI position alone, SoftBank has drawn comparisons to Masayoshi Son's famous Alibaba bet.

SoftBank trades on the Tokyo Stock Exchange (9984.T) and as an ADR in the US (SFTBY). Japanese retail investors have driven significant volume as the OpenAI thesis plays out.

High Intensity: Microsoft (MSFT)

Microsoft's 27% stake is the largest and most valuable in absolute terms (~$227B), but relative to Microsoft's ~$3.2 trillion market cap, OpenAI represents roughly 7% of the company's value. That's still enormous — it means roughly $7 of every $100 invested in Microsoft is an indirect OpenAI bet.

Beyond the equity, Microsoft benefits from the commercial relationship: Azure AI revenue, Copilot subscriptions powered by GPT models, and the broader "AI halo" driving enterprise cloud adoption. Microsoft has exclusive IP rights and Azure API exclusivity through 2032. It's the closest thing to owning OpenAI without owning OpenAI.

Moderate Intensity: Amazon (AMZN)

Amazon's $50 billion commitment makes it a major player, but with a ~$2.3 trillion market cap, even the full position would represent roughly 2% of Amazon's value. The bigger story is strategic: OpenAI committed to $100 billion in AWS spending over eight years and will deploy Amazon's Trainium chips. For Amazon, the OpenAI deal is as much about cloud revenue as equity upside.

Note the hedging: Amazon is simultaneously Anthropic's largest investor ($8B) and cloud partner. Owning AMZN gives you exposure to both frontier AI labs.

Lower Intensity: Nvidia (NVDA)

Nvidia's $30 billion stake is significant in dollar terms but represents well under 1% of Nvidia's ~$3.4 trillion market cap. The real value for Nvidia is ensuring OpenAI remains a massive GPU customer. Jensen Huang's comment that this may be his "last big investment" in AI labs suggests Nvidia views the equity position as strategic insurance rather than a financial investment.

ETF Exposure: ARK Innovation (ARKK)

Cathie Wood's ARK Innovation ETF held OpenAI as approximately 2.9% of the fund as of late January 2026 — its 9th-largest position. This makes ARKK one of the few retail-accessible vehicles with direct OpenAI private equity exposure, though it comes wrapped in ARK's broader high-conviction tech portfolio.

The Private Investors: Venture and Growth Funds

A significant slice of OpenAI's cap table sits with private funds. For institutional and ultra-high-net-worth investors, these represent another route to exposure.

Thrive Capital

Joshua Kushner's firm has been OpenAI's most consistent VC backer, participating in virtually every round since Series A. Thrive's relationship with OpenAI is so intertwined that OpenAI took a stake in Thrive Holdings in December 2025, creating a circular cross-investment. Thrive manages approximately $16 billion and its LP base includes major endowments and family offices.

Sequoia Capital

Sequoia participated in OpenAI's early venture rounds. As one of the world's largest VC firms managing over $85 billion, Sequoia's OpenAI exposure is likely distributed across its growth and global funds. Some institutional LPs in Sequoia funds gain indirect OpenAI exposure through their commitments.

Andreessen Horowitz (a16z)

a16z participated in OpenAI funding rounds and has been one of the most vocal AI bulls in venture capital. The firm manages approximately $42 billion across venture, growth, and crypto funds. Its LPs include university endowments, pension funds, and sovereign wealth funds.

Tiger Global, Coatue, Altimeter, Dragoneer

These crossover hedge fund / growth equity firms participated in various OpenAI rounds. For investors who are LPs in these firms' growth vehicles, there may be indirect OpenAI exposure in the portfolio.

Fidelity, T. Rowe Price, BlackRock, TPG

These institutional investors participated in the Series F and/or Series G. Importantly, Fidelity and T. Rowe Price manage mutual funds accessible to retail investors. Check holdings disclosures for funds like Fidelity Contrafund, Fidelity Blue Chip Growth, or T. Rowe Price Global Technology — some may hold OpenAI at a small weight.

Secondary Markets: Direct Pre-IPO Access

For accredited investors seeking direct OpenAI equity, secondary marketplaces offer pre-IPO access:

  • Hiive — Lists OpenAI shares with active buy/sell orders. Requires accredited investor status.
  • Forge Global — Facilitates pre-IPO share transactions with minimum investments typically $50,000-$250,000.
  • EquityZen — Another platform for accredited investors to access private company shares.
  • EquityBee — Focuses on funding employee stock options, providing another indirect route.

Secondary market pricing for OpenAI has been volatile, often trading at premiums to the last primary round valuation as IPO anticipation builds. Liquidity is limited and spreads can be wide — buyer beware.

The Stargate Factor

Any analysis of OpenAI exposure is incomplete without mentioning Stargate — the $500 billion joint venture between SoftBank, OpenAI, and Oracle (ORCL) to build massive AI data centers across the US. While Stargate isn't directly reflected in OpenAI's cap table, it ties together several publicly traded companies:

  • Oracle (ORCL) — Infrastructure partner providing data center capacity.
  • SoftBank (SFTBY) — Lead financial backer of Stargate.
  • Nvidia (NVDA) and AMD (AMD) — Chip suppliers for Stargate infrastructure.
  • Various power/utility companies — Stargate's multi-gigawatt energy needs benefit the broader infrastructure ecosystem.

The IPO: What We Know

OpenAI is targeting an IPO in the second half of 2026, with some analysts expecting a valuation above $1 trillion at listing. The PBC restructuring in October 2025 was widely seen as clearing the path for a public offering. Key considerations:

  • The IPO would allow early investors and employees to liquidate positions, while also enabling the conditional $35 billion Amazon tranche to close.
  • OpenAI's revenue trajectory ($13B+ annualized, growing rapidly) supports a premium valuation, though profitability remains a question mark given massive infrastructure spending.
  • As a public benefit corporation, OpenAI will have dual obligations to shareholders and its stated mission — an unusual structure for a public company of this scale.

Key Risks

  • Valuation risk: At $840 billion post-money and ~$13B revenue, OpenAI trades at roughly 65x revenue — even more aggressive than Anthropic's multiple.
  • Competition: Anthropic's Claude, Google's Gemini, Meta's Llama, and an expanding open-source ecosystem all challenge GPT's market position.
  • Structural complexity: The PBC structure, return caps for early investors, non-profit foundation ownership, and Sam Altman's zero-equity situation create governance questions that could surface during an IPO process.
  • Concentration risk: Three investors (Microsoft, SoftBank, Amazon) control roughly 46% of the company, creating potential conflicts of interest given their own competing AI ambitions.
  • Conditional commitments: Amazon's $35B second tranche depends on an IPO or AGI milestone — if neither occurs by late 2028, the commitment expires.
  • Infrastructure spending: OpenAI has committed to $100B in AWS spending and massive compute build-outs. These commitments create long-term cost obligations regardless of revenue trajectory.

Summary: How to Invest in OpenAI

Method Access Level Best For
Buy SFTBY / 9984.T (SoftBank) Anyone with a brokerage Maximum OpenAI concentration (~78% of mkt cap)
Buy MSFT (Microsoft) Anyone with a brokerage Largest absolute stake + commercial upside (~7% of mkt cap)
Buy AMZN (Amazon) Anyone with a brokerage Dual exposure (OpenAI + Anthropic)
Buy ARKK (ARK Innovation ETF) Retail investors Direct private OpenAI equity in an ETF wrapper (~3% weight)
Fidelity / T. Rowe Price mutual funds Retail investors Small, diversified OpenAI exposure
Secondary markets (Hiive, Forge, EquityZen) Accredited investors Direct pre-IPO equity ownership
VC fund LP commitments Institutional / UHNW Exposure through Thrive, Sequoia, a16z, etc.
Wait for the IPO (H2 2026) Everyone Direct ownership at scale, but likely $1T+ valuation

Disclaimer: This article is for informational and educational purposes only and does not constitute financial advice. Frontier Ledger is not a registered investment advisor. All investments carry risk, including the potential loss of principal. The ownership estimates presented are based on publicly available information and may not reflect actual positions. Always conduct your own research and consult a qualified financial professional before making investment decisions.