The numbers alone are enough to stop you mid-scroll. Amazon and Microsoft are each preparing to spend roughly $200 billion in 2026 building out data centers — an investment scale that has no historical precedent in the technology industry. The Amazon Microsoft cloud race, which has played out over nearly two decades, has entered a phase where the financial stakes are so elevated that even a hint of disappointment in quarterly earnings can wipe billions off a company’s market value overnight.
Summary
Key takeaways
- Amazon and Microsoft each plan to invest approximately $200 billion in data centers in 2026, driven by AI demand.
- AWS holds roughly 28% of the cloud market; Microsoft Azure holds about 21%, together commanding half the global market.
- AWS is forecast to reach $168 billion in net sales in 2026, while Azure and Microsoft cloud services are projected at $148.9 billion in fiscal 2027.
- Microsoft’s Intelligent Cloud business carries an estimated 47% operating margin, compared to AWS’s 35%, though different reporting structures complicate direct comparisons.
- Amazon’s free cash flow has fallen sharply to $1.2 billion over the past 12 months, while Microsoft’s stood at $73 billion — and they are funding expansion in fundamentally different ways.
A Spending Race Without Historical Parallel
What’s happening right now in cloud infrastructure is not a normal capital cycle. Both Amazon and Microsoft are pouring cash into land, power, and compute at a pace that would have seemed fantastical even five years ago. Amazon has guided to roughly $200 billion in capital expenditures across the company in 2026. Microsoft is spending at a comparable scale to fund its AI infrastructure buildout.
The driving force is AI. Both companies are building not just for today’s workloads, but for a generation of AI applications that are still in their infancy. The current handful of breakout AI products — coding tools, chat assistants — represents only the earliest fraction of what the infrastructure will eventually serve.
Amazon CEO Andy Jassy has been explicit that the spending is not speculative. “We’re not investing approximately $200 billion in capex in 2026 on a hunch,” he wrote in his annual shareholder letter. He noted that AWS must spend on capacity six to 24 months before it can bill customers, and that a substantial portion of the expected 2026 capex — much of which will be monetized in 2027 and 2028 — already has customer commitments behind it. That includes a commitment from OpenAI worth more than $100 billion.
Who Owns the Cloud — and Who Is Growing Faster
AWS vs Azure: Market Share and Revenue Forecasts
Amazon Web Services holds approximately 28% of the global cloud market, ahead of Microsoft Azure’s roughly 21%, according to Synergy data. Together, the two companies control about half the market, with Google Cloud occupying the third position at between 12% and 14% depending on the quarter. The gap between AWS and Azure matters, but what investors are watching more closely right now is the trajectory.
Based on Visible Alpha consensus estimates compiled by S&P Global, AWS is expected to reach $168 billion in net sales in 2026, up from $128.7 billion the prior year — a 30.7% increase. The margins attached to that revenue are striking: a 93.8% gross margin and an operating margin of approximately 35.4%.
Microsoft’s Azure and broader cloud services are projected to reach $148.9 billion in fiscal 2027, representing a roughly 40% jump from approximately $106 billion in fiscal 2026, which ended in June. Melissa Otto, Global Head of Visible Alpha Research at S&P Global, noted that Microsoft’s pace actually puts it slightly ahead of AWS on a growth-rate basis — though the comparison starts from a somewhat lower revenue base.
Backlogs and Customer Commitments Signal Long-Term Demand
Perhaps more telling than current revenues are the forward-looking commitment numbers. AWS carries a current backlog of $364 billion in remaining performance obligations — signed customer contracts representing future revenue — and that figure excludes the recently announced $100 billion deal with Anthropic, according to Bank of America analysts. AWS’s in-house chip revenue commitments reportedly exceed $225 billion.
Microsoft’s picture is similarly large, though harder to isolate. The company disclosed nearly $627 billion in remaining performance obligations, up 99% year-over-year — but that figure covers its entire commercial business, including Microsoft 365 and Dynamics, not just Azure.
The scale of these backlogs matters because it transforms what might look like a reckless spending bet into something more structured. The companies aren’t building speculatively; they are, at least in substantial part, building to fulfill contracts already signed.
Financial Performance and Capital Strategies Differ Significantly
Profitability and Operating Margins of AWS and Microsoft Intelligent Cloud
Microsoft’s Intelligent Cloud business carries an estimated operating margin of approximately 47%, higher than AWS’s 35%, according to Visible Alpha estimates cited by S&P Global. Otto described the Intelligent Cloud business as “very profitable… more profitable than AWS and growing faster.” The caveat is real, however: the Intelligent Cloud segment includes older, higher-margin server software, so the pure Azure margin would likely be lower than the blended figure.
Otto characterizes AWS and Azure less as direct competitors and more as “frenemies” with genuinely different positioning. AWS appeals to startups and large machine learning workloads through its flexibility and customizability, while Azure extends into enterprises already running Microsoft software, making adoption easier. The result is that when major companies go to market, they often end up buying both.
Cash Flow, Debt, and Funding Approaches
This is where the two companies diverge most sharply — and where investor concern is most concentrated. Amazon’s free cash flow fell to $1.2 billion over the past 12 months, down from $25.9 billion the year before. To fund the buildout, Amazon more than doubled its bond debt to more than $120 billion.
Microsoft is operating from a fundamentally different financial position. The company is not issuing new bonds. Instead, it is funding a buildout of roughly $35 billion per quarter directly from operating cash flow. Its free cash flow for the 12 months ending in March was $73 billion, up slightly year-over-year. The contrast is sharp: one company is leveraging its balance sheet aggressively, the other is writing checks from what it earns.
Analysts caution that directly comparing the two cash flow figures is complicated by differences in how Amazon and Microsoft structure their finances. But the directional signal is clear enough: Microsoft’s financial cushion is substantially larger, and its funding approach carries less balance-sheet risk heading into what could be an extended period before the AI infrastructure investment pays off.
What Investors Are Watching — and Why the Stakes Are This High
The context for this week’s earnings reports was set sharply by Alphabet’s experience. Last Thursday, Alphabet’s stock fell 7% after the company raised its capital expenditure projections and reported negative free cash flow in the second quarter. The market’s reaction signaled something important: investors are no longer willing to give unconditional credit for AI ambition. They want to see the financial discipline behind the spending.
For Amazon and Microsoft, the scrutiny will focus on revenue growth, profit margins, customer backlogs, and returns on capital. Luke Rahbari, CEO of Equity Armor Investments, who holds both stocks across multiple portfolios, put the competitive logic bluntly: “Whoever controls the money controls the winners. You’ve got to soak up as much money as you can so there isn’t as much money available to other players.”
Both Amazon and Microsoft are two of the five largest weights in the S&P 500, together comprising 8% to 9% of the index. That means virtually anyone saving for retirement has indirect exposure to the outcome of this cloud rivalry. Microsoft’s stock trades at roughly 23 times expected earnings; Amazon’s at about 27 times, according to S&P Capital IQ data. Year-to-date, Microsoft’s stock is down approximately 19%, while Amazon has been broadly flat, up around 2.5%.
The deeper analytical question is not whether the demand for AI cloud services is real — the backlog figures strongly suggest it is — but whether the timeline for monetizing the investment is compatible with investor patience. AWS acknowledges that capacity built now will largely be monetized in 2027 and 2028. Microsoft has signaled the company is prioritizing its own AI products for scarce GPU capacity before allocating the remainder to Azure customers, a trade-off that has triggered investor scrutiny.
The products that will ultimately justify the infrastructure are still being developed. Whether investors grant both companies the runway to reach that moment — without further punishing their stocks — is the real question hanging over earnings season.
FAQ
How much are Amazon and Microsoft planning to invest in data centers in 2026?
Both Amazon and Microsoft plan to spend roughly $200 billion each on building out data centers in 2026, representing an unprecedented level of capital expenditure in the technology industry.
What is the current market share of AWS and Microsoft Azure?
Amazon Web Services holds approximately 28% of the global cloud market, while Microsoft Azure holds roughly 21%, according to Synergy data. Together they account for about half the market, with Google Cloud in third place.
How are Amazon and Microsoft funding their cloud expansion differently?
Amazon has increased its bond debt to more than $120 billion to help fund its expansion, with free cash flow falling sharply to $1.2 billion over the past 12 months. Microsoft, by contrast, is primarily funding its buildout of roughly $35 billion per quarter through operating cash flow without issuing new bonds, and reported $73 billion in free cash flow for the 12 months ending in March.
What financial metrics will investors focus on in upcoming earnings reports?
Investors will scrutinize revenue growth, profit margins, customer backlogs, and returns on capital investments for both companies, with particular attention to whether the enormous capex commitments are translating into durable revenue and margin expansion.
Article produced with the assistance of artificial intelligence and reviewed by the editorial team.
