The biggest tech firms have spent the last few years buying pieces of the labs that build AI. They pay in cash and in computing power, and in return they get a slice of the lab, the right to use its models and, often, a big customer for their own data centers. That mix makes each deal hard to sum up in one number.
The number people quote is often out of date. A lab that raises money every few months keeps shrinking each older investor's slice, and the headline figure from one round is still being shared long after the next round has changed it. It also leaves out half the story, because the same partner can be an owner, a supplier and a customer at once.
The clearest picture comes from the two firms' own words. A listed investor has to say in its annual report what it owns and how it counts it. When the terms change, both sides tend to post the new terms on the same day. Read together, those papers give the size of the stake, what it earns and what each side still owes the other.
Microsoft and OpenAI are the best-known pair, and their deal has changed twice, in October 2025 and April 2026. BloFin lists Microsoft (MSFT) as the MSFTUSDT Perpetual, a USDT-margined contract you can hold long or short with leverage, so news about OpenAI can reach your position the same day.
What is Microsoft's OpenAI stake?
Microsoft's OpenAI stake is a holding of about 24%, counted on an as-converted basis and booked as an equity method investment, according to its quarterly filing for July to September 2026 (source: Microsoft Form 10-Q for the quarter to September 30, 2026). The 27% you often see is an older figure Microsoft gave in October 2025 (source: Microsoft blog, October 28, 2025).
These figures are all Microsoft's own, written about a year apart. In October 2025 OpenAI turned its business into a public benefit corporation, and Microsoft said its holding was then worth about $135 billion and came to roughly 27% of the new company. That count took in every owner, from staff to the OpenAI Foundation (source: Microsoft blog, October 28, 2025). OpenAI then kept raising money. By June 30, 2026 Microsoft's annual report put the stake at about 25%, and it puts the drop down to the overhaul and to OpenAI's later fundraising (source: Microsoft Form 10-K for fiscal 2026). Three months later, at the end of September, the quarterly report gave about 24% (source: Microsoft Form 10-Q).
"As-converted" means every preferred share and convertible note is counted as if it had already turned into a plain share, which is the fair way to compare the owners of a private firm. So the honest answer to "how much of OpenAI does Microsoft own?" is just under a quarter. The figure has slipped as OpenAI has sold new shares to other investors.
Figure | Date it describes | Basis | Who says it |
|---|---|---|---|
32.5% | Before OpenAI's latest rounds, 2025 | As-converted, OpenAI's for-profit arm | Microsoft blog, October 28, 2025 |
About 27%, worth about $135 billion | Right after the October 2025 overhaul | As-converted, diluted, all owners | Microsoft blog, October 28, 2025 |
About 25% | June 30, 2026 | As-converted | Microsoft Form 10-K for fiscal 2026 |
About 24% | September 30, 2026 | As-converted | Microsoft Form 10-Q, July to September 2026 |
For a Microsoft investor, the stake is one part of a much larger business. Most of Microsoft's money comes from cloud services and software sold by subscription, as the breakdown of how Microsoft makes money shows. The OpenAI holding sits next to those businesses as an investment, outside the two segments Microsoft reports.
How Microsoft's OpenAI stake grew since 2019
Microsoft first put money into OpenAI in July 2019 and kept adding through several rounds. By September 30, 2026 it had pledged $13.0 billion and paid in $12.0 billion of it (source: Microsoft Form 10-Q). Along the way, its share went from 32.5% to about 27%, then about 25% and, at the end of September 2026, about 24%.
The first deal was a computing tie-up as much as an investment. In July 2019 Microsoft announced a $1 billion investment in OpenAI, along with a plan to build AI supercomputers on Azure, its cloud (source: Microsoft News, July 22, 2019). More money followed. In January 2023 the press reported terms that neither firm confirmed: Microsoft would take 75% of OpenAI's profits until it got its money back, then hold 49% (source: SiliconANGLE). That 49% is still repeated today, while Microsoft's own posts and filings have put the stake between 32.5% and about 24%.
The March 2026 round shows why the share keeps slipping. OpenAI raised $122 billion at a value of $852 billion after the new money, with Amazon, Nvidia and SoftBank as the anchor investors and Microsoft taking part again (source: OpenAI, March 31, 2026). When that much new money buys in, every older owner's slice gets smaller, even an owner who adds a little.
Date | Event | Microsoft's position |
|---|---|---|
July 2019 | First investment and Azure computing deal | $1 billion invested |
January 2023 | More investment; press reports of a profit-share deal | 49% after payback (reported, never confirmed) |
October 2025 | OpenAI becomes a public benefit corporation | 32.5% before recent rounds; about 27% after, worth about $135 billion |
March 2026 | OpenAI's $122 billion funding round, with Microsoft taking part | Further diluted |
June 30, 2026 | Microsoft's fiscal year ends | About 25%; $13.0 billion pledged, $11.9 billion paid in |
September 30, 2026 | Microsoft's July to September quarter ends | About 24%; $13.0 billion pledged, $12.0 billion paid in |
The cash Microsoft has paid in is small next to what the stake is worth. By September 30, 2026 it covered 92.3% of the pledge, which left about $1.0 billion still to pay (source: Microsoft Form 10-Q). Set against the $135 billion Microsoft put on its holding in October 2025, the money it has put in has grown many times over on paper.
How the OpenAI stake shows up in Microsoft's earnings
Microsoft books its OpenAI stake under the equity method, so its share of the changes in OpenAI's value lands in other income, below operating income. From July to September 2026 that added $207 million to net income, against a $3.1 billion loss a year earlier (source: Microsoft Form 10-Q). Microsoft's adjusted EPS leaves it out, keeping the main business in view.
The equity method is the rule a company uses when it owns enough of another firm to sway it but not to run it. The owner books its share of the other firm's gains and losses each quarter, with no market price involved. Microsoft uses a version called hypothetical liquidation at book value, because its rights in a sale or wind-down differ from its plain share of ownership. Under it, Microsoft's gain or loss each quarter is the change in what it would get back if OpenAI were wound up at book value (source: Microsoft Form 10-Q).
That is why the line can swing hard both ways. When OpenAI's book value falls, the amount Microsoft would get back falls with it, and Microsoft books a loss, as it did from July to September 2025. When a new round dilutes Microsoft at a higher price, Microsoft books a dilution gain instead. Its annual report traces most of the fiscal 2026 gain to the dilution from OpenAI's 2025 overhaul (source: Microsoft Form 10-K for fiscal 2026).
Fiscal quarter | Calendar months | Effect on net income | Effect on earnings per share |
|---|---|---|---|
Q1 FY2026 | July to September 2025 | −$3.1 billion | −$0.41 |
Q2 FY2026 | October to December 2025 | +$7.6 billion | +$1.02 |
Q3 FY2026 | January to March 2026 | −$14 million | Minimal |
Q4 FY2026 | April to June 2026 | +$480 million | +$0.07 |
Q1 FY2027 | July to September 2026 | +$207 million | +$0.03 |
The four fiscal 2026 quarters add up to about $5.0 billion after tax, the full-year figure Microsoft gives alongside $0.67 a share, while the rounded quarterly per-share figures sum to $0.68 (source: Microsoft Q4 fiscal 2026 results). That gain was 3.7% of Microsoft's $133.7 billion net income for the year. Before tax, the OpenAI line was a $6.5 billion gain in fiscal 2026, after a $4.8 billion loss in fiscal 2025 (source: Microsoft Form 10-K for fiscal 2026). From July to September 2026 it was a $272 million gain before tax, against a $4.1 billion loss in the same months of 2025 (source: Microsoft Form 10-Q).
The swings are big enough to bend a single quarter. From October to December 2025, OpenAI gains made up $1.02 of Microsoft's $5.16 reported EPS, which is 19.8% (source: Microsoft Q2 fiscal 2026 results). From July to September 2026 the gap was small, with reported EPS of $4.92 against adjusted EPS of $4.89 (source: Microsoft Q1 fiscal 2027 results). Microsoft's adjusted figures remove just one item: the net gains and losses on its OpenAI stake (source: Microsoft Form 10-Q). For fiscal 2026, adjusted EPS was $17.28 against $17.95 reported (source: Microsoft Form 10-K for fiscal 2026). When you read a Microsoft headline, check which of the two numbers it uses, since in a quarter like October to December 2025 they can differ by a fifth.
Because the OpenAI line lands in reported profit each quarter, it can change Microsoft's headline EPS on report day. Microsoft reported its July to September 2026 quarter on Wednesday, October 28, 2026, after the US market closed, and its next report covers October to December 2026. You can watch how Microsoft's price reacts to each release on the MSFTUSDT Perpetual page.
The April 2026 terms: Revenue share, license and cloud
On April 27, 2026 Microsoft and OpenAI changed their deal. Microsoft stopped paying OpenAI a revenue share, while OpenAI keeps paying Microsoft through 2030 at the same rate, up to a total cap. Microsoft's license to OpenAI's models runs through 2032 but is no longer exclusive, and OpenAI can now sell all its products on any cloud.
Microsoft posted the five new points on its blog (source: Microsoft blog, April 27, 2026), and OpenAI posted the same five points, word for word, on its own site (source: OpenAI, April 27, 2026). Four of them change a term of the October 2025 deal, and the fifth keeps Microsoft as a major shareholder.
Term | October 2025 agreement | April 2026 amendment |
|---|---|---|
Revenue share | Runs until an expert panel verifies AGI, paid over a longer period | OpenAI pays Microsoft through 2030, "independent of OpenAI's technology progress", same rate, total cap; Microsoft pays OpenAI nothing |
License to OpenAI's models and products | Exclusive until AGI; extended through 2032, including models after AGI | Through 2032, now non-exclusive |
Cloud | Azure API exclusivity until AGI; new $250 billion Azure purchase | Azure stays the main cloud and gets products first; OpenAI can serve every product on any cloud |
Ownership | About 27% after the overhaul | Microsoft remains a major owner |
The revenue share now runs one way, from OpenAI to Microsoft, where until April money also flowed from Microsoft to OpenAI. The other big change is the end date. Under the October 2025 terms, the payments lasted until an outside panel confirmed that OpenAI had reached artificial general intelligence (AGI), meaning AI that matches people at most work. The new wording fixes the end at 2030, whatever OpenAI's research achieves.
Some figures are missing from both posts. Neither firm has published the revenue-share rate or the size of the cap. The dollar caps and rates quoted in some reports come from people briefed on the deal and are unconfirmed. What Microsoft's latest quarterly report does confirm is that the revenue-share payments to Microsoft go on (source: Microsoft Form 10-Q).
OpenAI models on Google Cloud
On October 21, 2026 OpenAI said its frontier models and its Codex coding agent are coming to Google Cloud, where business customers can buy them through Google's marketplace. It is the clearest sign yet of what the April 2026 terms allow, and OpenAI's post ends by stating that "Microsoft remains OpenAI's primary cloud partner" (source: OpenAI, October 21, 2026).
The detail that matters for Microsoft is how the sales are counted. OpenAI says Google Cloud customers who have already promised Google a set amount of spending can count these purchases against that promise. So a company with a Google budget to use up can now spend part of it on OpenAI's models. Under the October 2025 terms, OpenAI's API was exclusive to Azure until AGI, so cloud buyers of OpenAI's models went through Microsoft. OpenAI says wide release is planned in the coming weeks, so sales through Google have yet to show up in anyone's results.
Microsoft still has two ways to gain when OpenAI sells elsewhere. Its stake gains value if OpenAI's sales grow, and the revenue share OpenAI pays it goes on at the same rate through 2030, up to the cap. What it gives up is the sole route to OpenAI's models through a cloud, which mattered most to Azure. Amazon sits on the other side of this shift, as both an OpenAI investor and a cloud supplier, as the page on Amazon's OpenAI stake shows.
OpenAI as an Azure customer: The $250 billion commitment
OpenAI is one of Microsoft's largest customers as well as an investment. From July to September 2026 Microsoft booked $10.0 billion of revenue from OpenAI, counting revenue-share payments, which is 10.8% of its $92.3 billion total. OpenAI owed it $7.2 billion at September 30, up from $6.0 billion at June 30 (source: Microsoft Form 10-Q).
For fiscal 2026 the figure was $24.1 billion, or 7.3% of revenue (source: Microsoft Form 10-K for fiscal 2026). The bigger number is still ahead. As part of the October 2025 deal, OpenAI "contracted to purchase an incremental $250B of Azure services" (source: Microsoft blog, October 28, 2025). Deals like that sit in Microsoft's backlog of signed sales it has yet to deliver, which reached $678 billion on June 30, 2026, 84% more than a year before. On the July 2026 earnings call, finance chief Amy Hood said the backlog "increased 25% when excluding OpenAI". Taken together, those two growth rates mean at least seven-tenths of that year's jump came from this one customer (source: Microsoft Q4 fiscal 2026 earnings call). By September 30, 2026 the backlog was $677 billion, up 73%. Microsoft's October report named no OpenAI share of it (source: Microsoft Q1 fiscal 2027 results).
That weight on one customer is why OpenAI's ability to pay matters to Microsoft's owners. In March 2026 OpenAI said it was earning about $2 billion a month (source: OpenAI, March 31, 2026). At that March 2026 pace of $24 billion a year, the $250 billion Azure purchase equals about 10.4 years of OpenAI's sales. Azure is one of several big computing deals OpenAI has signed, including AMD's deal with OpenAI. OpenAI pays for them with fast-growing sales and very large funding rounds, so a slowdown in either would reach Microsoft's backlog. That risk is one strand of the bear case for Microsoft stock.
What the stake is worth on paper
A rough market value for Microsoft's stake comes from multiplying its share by the price of OpenAI's March 2026 funding round. About 24% of that $852 billion value is about $204.5 billion. Set against Microsoft's own market value of about $3.9 trillion at the October 28, 2026 close, that is 5.2%.
That market value comes from Microsoft's 7,426,194,552 shares outstanding on October 22, 2026 (source: Microsoft Form 10-Q) and its $531.01 close on October 28 (source: Yahoo Finance MSFT history). The result is a paper figure, and it comes with three caveats. The 24% is for September 30 (source: Microsoft Form 10-Q), while the $852 billion is for March 31 (source: OpenAI, March 31, 2026). A private funding price is set by a few large buyers, with no daily trading behind it. And Microsoft's books carry the stake under the equity method, so its accounts do not show the stake at this value.
Measure | What it uses | Where you see it |
|---|---|---|
Microsoft's October 2025 value | About 27% of OpenAI after the overhaul | About $135 billion, in Microsoft's own post |
Paper value at the March 2026 price | About 24% × $852 billion | About $204.5 billion, from multiplying the two |
Book treatment | Equity method, hypothetical liquidation at book value | Gains and losses in other income each quarter |
The gap between the paper value and the book figure is why an OpenAI listing would matter to Microsoft. A public share price would give the stake a daily market value anyone could check, in place of an occasional funding price. The listing itself, its timing and OpenAI's own finances belong to the story of OpenAI's planned IPO.
Microsoft's own AI models beside OpenAI
Microsoft is building its own AI models, called MAI, so that it leans less on any one lab. In November 2025, nine days after the October 2025 terms first let it chase AGI on its own, it formed the MAI Superintelligence Team under Mustafa Suleyman, the head of Microsoft AI (source: Microsoft AI, November 6, 2025).
The October 2025 deal freed Microsoft to chase AGI by itself or with other partners (source: Microsoft blog, October 28, 2025). Suleyman's post named the new team and its goal, which he calls humanist superintelligence: very capable AI aimed at specific problems and kept under human control. On the July 2026 call, Satya Nadella said Microsoft's Maia 200 AI chip now runs both OpenAI and MAI models. He added that Microsoft's model catalog for developers carries the latest models from OpenAI, Anthropic, Mistral and xAI as well as its own MAI family (source: Microsoft Q4 fiscal 2026 earnings call).
That is a hedge more than a split. Microsoft keeps its license to OpenAI's models through 2032 and sells access to rival labs' models next to them. It owns part of one of those rivals too, as the page on Microsoft's Anthropic stake explains. For an investor, that spreads Microsoft's AI supply across several labs, its own included.
Trading Microsoft when OpenAI news lands
OpenAI news can move Microsoft's share price because it touches the stake, the revenue share and the Azure backlog at once. On BloFin you trade that price through the MSFTUSDT Perpetual, a USDT-settled contract with up to 20x leverage. It gives you no share, dividend or vote, as the guide to how the MSFTUSDT Perpetual works explains.
The contract follows US market hours. Under BloFin's stock futures notice, trading can switch to reduce-only orders when the US market is shut, which covers weekday evenings, weekends and US market holidays (source: BloFin stock futures notice). So if OpenAI news lands after the 4PM ET close, you may only be able to shrink or exit a position until the 9.30AM ET open the next trading day. In UTC, that window runs from 8PM to 1.30PM in summer and from 9PM to 2.30PM in winter. The rules for each window, and how they shift when US daylight saving time ends, are set out in MSFTUSDT trading hours and reduce-only windows.
Say you hold a long MSFTUSDT position of 10 MSFT at $531.01, Microsoft's October 28, 2026 close, a position worth $5,310.10, and news after the close cuts the value of Microsoft's stake. If Microsoft opens 3% lower the next morning, the position loses about $159.30 before fees. At 10x leverage that is about 30% of the $531.01 margin behind it. Holding overnight also means paying or receiving funding payments, which BloFin normally settles at 12AM, 8AM and 4PM UTC each day.
Looking to trade Microsoft as OpenAI news unfolds? To get started, you'll need to first create a BloFin account, fund your account with cryptocurrency, and go to the MSFTUSDT Perpetual trading page.
Frequently asked questions
Does Microsoft own 49% of OpenAI?
No. Microsoft's 10-Q for July to September 2026 puts its holding at about 24% of OpenAI, counted as if all of OpenAI's preferred shares had turned into plain shares. The 49% figure comes from January 2023 press reports of a deal in which Microsoft would first take 75% of OpenAI's profits until it got its money back, and only then hold 49%. Neither firm confirmed those terms at the time.
Does Microsoft own ChatGPT?
ChatGPT belongs to OpenAI. Microsoft owns about 24% of OpenAI and holds a license to OpenAI's models and products through 2032, which lets it build OpenAI's tech into its own products such as Copilot. Since October 2025 that license also covers models made after AGI, while Microsoft's rights to OpenAI's research methods last until 2030 or until an expert panel confirms AGI, whichever comes first.
Who decides whether OpenAI has reached AGI?
An outside expert panel. Under the October 2025 agreement, if OpenAI says it has reached artificial general intelligence, a panel of outside experts now checks that claim. Its verdict used to decide when Microsoft's revenue share and some of its rights would end. Since April 2026 the revenue share runs to 2030 either way, so the panel's verdict now matters mainly for Microsoft's rights to OpenAI's research methods.
Can Microsoft build AGI on its own?
Yes. The October 2025 agreement lets Microsoft pursue AGI on its own or with other partners. If it uses OpenAI's tech to do so before AGI is declared, its models must stay under computing limits that Microsoft described as far larger than the systems used to train leading models in 2025. Microsoft's MAI Superintelligence Team, formed in November 2025, leads its own work on the most advanced models.
Does holding the MSFTUSDT Perpetual give you part of the OpenAI stake?
A position in the MSFTUSDT Perpetual tracks Microsoft's share price, so changes in the stake's value reach you only through that price. BloFin's stock futures notice says the contracts give you neither the shares nor any dividend, vote or other right a shareholder has. A Microsoft shareholder owns the stake indirectly, as part of what one Microsoft share gives you; a perpetual holder owns a price exposure.
Researched and written by the BloFin Academy editorial team with AI-assisted drafting. All facts independently verified. Primary sources include Microsoft's 10-Q for July to September 2026, its 10-K for fiscal 2026, its quarterly results and its July 2026 earnings call. They also include blog posts by Microsoft and OpenAI, Microsoft AI, SiliconANGLE and Yahoo Finance data for MSFT. BloFin's source is its stock futures notice, current as of October 29, 2026.
Nothing in this article constitutes financial advice, and nothing in it is a recommendation to buy, sell or hold Microsoft in any form. The value of Microsoft's OpenAI stake rests on a private firm whose funding, spending and deals can change fast. A write-down, a lost customer pledge or a split between the two firms could hit Microsoft's profit and share price. The MSFTUSDT Perpetual gives you no share in Microsoft or OpenAI, and it may be reduce-only when news breaks outside US hours. At high leverage, a move of a few percent can wipe out your margin. Past performance does not indicate future results. Do your own research and consider your risk tolerance before you trade on BloFin.