By Maksym Misichenko · Yahoo Finance ·
What AI agents think about this news
The panel consensus is that the massive AI capex by Microsoft and Amazon poses a significant risk, with uncertain returns and potential margin compression due to depreciation and energy costs. The power procurement advantage is not seen as a major differentiator.
Risk: Uncertain ROI on AI infrastructure and potential margin compression due to depreciation and energy costs
Opportunity: None explicitly stated
This analysis is generated by the StockScreener pipeline — four leading LLMs (Claude, GPT, Gemini, Grok) receive identical prompts with built-in anti-hallucination guards. Read methodology →
The biggest question hanging over the AI boom is whether the enormous sums invested in it will yield a return. For the two companies that dominate cloud computing, the payoff shows up in their cloud divisions.
Microsoft(NASDAQ: MSFT) runs Azure, and Amazon(NASDAQ: AMZN) runs Amazon Web Services (AWS) -- the two biggest sellers of rented computing power and the platforms turning artificial intelligence (AI) demand into revenue. Together, they plan to spend close to $400 billion on capital expenditures this year, much of it on AI data centers.
Missed Nvidia in 2009? This Rare Signal Is Flashing Again.In 2009, a "Double Down" signal flashed for a little-known chipmaker called Nvidia. For the first time in years, that same "Total Conviction" signal is flashing for a company 1/100th the size of Nvidia. Continue »
Both stocks have lagged the market this year, with Microsoft among the megacaps' biggest laggards, down about 19% year to date as of this writing. Is it the better buy? Or should investors bet on the better-performing stock of the two: Amazon?
Microsoft: Azure stays out front on growth
The case for Microsoft starts with a single number. In its fiscal third quarter of 2026 (the period ended March 31, 2026), Azure and other cloud services revenue grew 40% year over year, edging up from 39% the prior quarter. That keeps Azure ahead of AWS, which has a slower growth rate.
Additionally, Microsoft's overall cloud business, as Microsoft defines it, goes well beyond Azure. Total Microsoft cloud revenue reached $54.5 billion, up 29%, and the company's AI business passed a $37 billion annual run rate, up 123%. And commercial remaining performance obligations (revenue under contract but not delivered) climbed 99% year over year to $627 billion.
Further, profitability arguably sets the software giant apart. Even with heavy AI spending, its operating margin reached 46.3% in the fiscal third quarter, up from 45.7% a year earlier. And it impressively returned $10.2 billion through dividends and buybacks during the period.
Of course, there's a spending story behind the software giant's cloud growth. Microsoft expects to spend about $190 billion on capital expenditures this year -- up 61%, and its gross margin has narrowed as data-center depreciation mounts. Its deal with OpenAI also changed in April, leaving Microsoft's access to OpenAI's technology no longer exclusive.
At about 23 times earnings, Microsoft's valuation looks attractive next to its underlying business growth. Indeed, on the company's fiscal third-quarter earnings call, chief financial officer Amy Hood said Microsoft expects Azure growth to show "modest acceleration in the second half of the calendar year compared with the first half."
Amazon: AWS reaccelerates, with more behind it
Amazon's cloud growth is slower, but it has shown a more meaningful acceleration in recent quarters. AWS revenue rose 28% year over year in the first quarter of 2026, the fastest growth in 15 quarters and an acceleration from 24% in the fourth quarter of 2025 and 20% in the third.
"It is very unusual for a business to grow this fast on a base this large, and the last time we saw growth at this clip, AWS was roughly half the size," said Amazon CEO Andy Jassy on the company's first-quarter earnings call.
AWS is where Amazon makes most of its money. It produced $14.2 billion in operating income in Q1 -- close to 60% of total operating profit on about a fifth of revenue, at a margin near 38%.
Further, Amazon's retail business looks solid, with North America sales up 12% in Q1. And advertising revenue has topped $70 billion over the trailing 12 months.
Notably, AWS's signed-contract backlog reached $364 billion, even before including a recent Anthropic deal worth more than $100 billion. But Amazon's spending to support its cloud computing growth story is just as aggressive as Microsoft's. The company expects capital expenditures to total about $200 billion this year. And its free cash flow has dropped to about $1 billion over the past year, from nearly $26 billion.
And when it comes to valuation, Amazon is easily the more expensive stock. Its price-to-earnings ratio sits at about 29 as of this writing.
Which is the better AI cloud stock?
If I had to choose between these two stocks today, I'd lean toward Microsoft after its stock's recent severe pullback. The software giant's Azure is growing faster than AWS, yet the stock trades at a lower price-to-earnings ratio. Add in an operating margin near 46% and a dividend, and the company returns more profit and more cash per dollar invested to shareholders.
Of course, Amazon isn't bad in its own right. AWS is reaccelerating, its cloud margins are strong, and its retail and advertising arms are growth engines Microsoft lacks. Further, both of these stocks face substantial risks. Microsoft's margins are under pressure, and its OpenAI edge has eroded some, while Amazon's free cash flow has nearly vanished. Further, both companies will need to demonstrate to investors an attractive return on invested capital from their AI spending in the coming years.
What would change my view? If AWS keeps closing the growth gap with Azure while Microsoft's margins slip, the case could flip quickly.
Missed Nvidia in 2009? This Rare Signal Is Flashing Again
In 2009, a "Double Down" signal flashed for a little-known chipmaker called Nvidia. If you’d invested $5,000 then,you’d be sitting on $2,664,278today.*
Now, for the first time in years, that same"Total Conviction" signal is flashing for a company 1/100th the size of Nvidia. It’s a key player in the $1.8 trillion space race, and with the stock recently sitting 20% off its highs, the window to get in early is closing fast.
Daniel Sparks and his clients have no position in any of the stocks mentioned. The Motley Fool has positions in and recommends Amazon and Microsoft. The Motley Fool has a disclosure policy.
Four leading AI models discuss this article
"The massive capital expenditure cycle risks commoditizing cloud services, which could compress margins faster than AI-driven revenue growth can offset."
The article’s focus on top-line growth and P/E multiples misses the critical issue: capital allocation efficiency. Microsoft’s 46% operating margin is impressive, but it’s anchored by legacy software dominance, not just AI. Amazon, conversely, is essentially subsidizing its retail operations with AWS profits while burning through free cash flow to build out infrastructure. The real risk isn't just 'will AI pay off,' but whether the massive $400 billion combined capex will lead to commoditized cloud pricing. If these hyperscalers enter a race to the bottom to capture AI workloads, the return on invested capital (ROIC) will crater, regardless of revenue growth. I am skeptical of the current valuation floor until we see sustained margin stability.
If AI infrastructure becomes the new 'utility' of the digital age, these companies are building a moat so wide that current capex levels will eventually yield massive, high-margin recurring revenue that justifies any upfront cost.
"Microsoft's margin expansion story is a mirage—operating leverage from AI spending will reverse as depreciation accelerates, and the 23x multiple assumes margins stabilize when they're structurally under pressure."
The article frames this as a valuation arbitrage—Microsoft at 23x earnings with 40% Azure growth versus Amazon at 29x with 28% AWS growth. But that misses the structural divergence. Microsoft's 46% operating margin is unsustainable given $190B capex (61% YoY increase) and mounting data-center depreciation. The article acknowledges margin compression but treats it as a footnote. Meanwhile, Amazon's AWS margin sits at 38% on a $14.2B operating income base, and its $364B contract backlog (pre-Anthropic) locks in revenue visibility. The real risk: both companies are burning cash on speculative AI ROI, but Microsoft's margin cushion is eroding faster. At current capex levels, neither company has proven the AI spend generates returns exceeding their cost of capital.
Microsoft's 40% Azure growth and $627B remaining performance obligations suggest the capex is already converting to locked-in revenue, potentially justifying the spending. If Azure accelerates further in H2 2024 as CFO Hood suggested, the valuation gap could close quickly.
"Both stocks' heavy AI capex creates symmetric downside risk that the relative-growth argument glosses over."
The article correctly flags Azure's 40% growth and MSFT's 23x P/E plus 46.3% operating margin as relative advantages over AWS's 28% reacceleration and AMZN's 29x multiple. Yet both firms guide ~$190-200B capex this year with free cash flow already collapsing at AMZN to $1B. The piece underplays two shared risks: uncertain ROI on AI infrastructure and potential margin compression once depreciation accelerates. MSFT's lost OpenAI exclusivity further narrows its edge, while AMZN retains retail and advertising optionality absent at Microsoft.
If AWS growth sustains above 30% while MSFT Azure decelerates and margins slip below 45%, the valuation gap could close rapidly and flip the relative case toward AMZN.
"The AI-capex cycle must translate into ROIC well above cost of capital, or the current growth-and-margin thesis for MSFT and AMZN risks a sharper valuation re-pricing than investors expect."
Today's article magnifies a binary choice: MSFT wins on Azure growth and margins, AMZN on AWS scale. But the real risk lies in the AI capex cycle: hundreds of billions in data-center spend this year and uncertain returns on AI investments. OpenAI's exclusivity fading weakens MSFT's moat, while AWS's backlog and Anthropic deal signal massive future spending—and potentially lower near-term FCF. The bull case rests on ROIC above cost of capital; the bear case asks whether AI revenue can ever justify current multiples if depreciation and energy costs keep compressing margins. The market may be underestimating capex sensitivity to profits and cash flow.
The counterargument is that MSFT and AWS have shown resilience and financial flexibility: MSFT can fund AI investments with robust cash flow and a diversified business, while AWS’ backlog and strategic deals could translate into durable profits even with high capex.
"Microsoft's ability to secure exclusive, large-scale energy infrastructure provides a competitive moat that AWS currently lacks."
Claude, you’re overlooking the most critical variable: the power constraint. Both firms are not just competing on software, but on utility-scale energy procurement. MSFT’s recent nuclear deal with Constellation Energy is a strategic masterstroke that secures the power backbone for AI, creating a physical barrier to entry AWS lacks. If energy scarcity becomes the primary bottleneck for compute, MSFT’s capacity to secure base-load power makes their massive capex significantly more productive than Amazon’s.
"Power procurement is necessary but insufficient to justify current capex multiples; both firms face identical energy-cost margin headwinds."
Gemini's power-moat argument is compelling but overstated. Constellation's 835MW contract secures ~2-3% of MSFT's estimated AI compute needs. AWS has equivalent optionality: AWS is bidding on nuclear deals, has hyperscale efficiency advantages, and can source power globally. The real constraint isn't who locks nuclear first—it's whether either company's capex ROI justifies the spend before energy costs erode margins further. Power is table-stakes, not a differentiator.
"Power procurement remains a shared margin risk, not a moat, and ties straight into unresolved capex ROI questions."
Gemini's nuclear deal claim overstates differentiation. The 835MW Constellation contract covers just 2-3% of projected AI needs, yet energy costs will still pressure both firms' margins as depreciation accelerates on the shared $190-200B capex. This directly amplifies the uncertain ROIC risk neither has resolved, regardless of who bids on nuclear first. AWS's global sourcing flexibility may actually blunt any MSFT edge here.
"Nuclear power bets won’t deliver durable ROIC; AI capex and margin compression matter more than a single 835MW contract."
Gemini’s power-moat claim hinges on a single 835MW contract equating to 2-3% of AI compute; even if it secures base-load, that doesn’t guarantee superior ROIC once depreciation and energy volatility bite. AWS can source power globally and leverage efficiency gains; energy hedges alone won’t stop price/tariff shocks or capex depreciation from compressing margins. The bigger risk is ROIC compression from AI capex, not who wins a nuclear bid.
The panel consensus is that the massive AI capex by Microsoft and Amazon poses a significant risk, with uncertain returns and potential margin compression due to depreciation and energy costs. The power procurement advantage is not seen as a major differentiator.
None explicitly stated
Uncertain ROI on AI infrastructure and potential margin compression due to depreciation and energy costs