Microsoft and Google are each spending about half a billion dollars a day on AI. This week, investors rewarded one and punished the other. The difference was cash.
The race to build artificial intelligence has reached a new stage. For two years, investors cheered every dollar that big tech companies spent on AI. Now they want to see the money coming back.
This week’s results from two of the biggest players, Microsoft and Alphabet, the owner of Google, showed the new mood clearly.
Microsoft spent heavily and still produced a large pile of cash. Its shares rose. Alphabet spent even more, and its cash went the other way. Its shares fell sharply.
Half a billion dollars a day
The numbers are hard to picture, so here is a simple way to see them.
In the three months to September, Alphabet spent $51.4 billion on what companies call capital expenditure: data centres, computer chips, buildings and power. That is about $560 million every day.
Microsoft spent $45.2 billion in the same period, about $490 million a day.
Together, the two companies spent about $1 billion a day building the machines that run AI.
Microsoft: spending, but still making cash
Microsoft’s cloud business, Azure, grew 48% to $33.2 billion in the quarter, according to the company’s official results. Total revenue rose 19% to $92.3 billion.
Most importantly for investors, Microsoft still had $18.6 billion in free cash flow, about $10 billion more than analysts had expected.
Microsoft also lowered its estimate for spending this year, from about $190 billion to about $170 billion. The company said this was because some data centre capacity is arriving late, not because demand has dropped.
Alphabet: fast growth, but the cash is going out
Alphabet’s results told a different story.
Google Cloud, which rents computing power to other businesses, had a huge quarter. Its revenue more than doubled, from $15.2 billion a year ago to $30.7 billion, according to Alphabet’s results.
But Alphabet spent so much on AI that its free cash flow fell to minus $9.1 billion. A year earlier, it was plus $24.5 billion. Growth in Google Search, the company’s biggest money-maker, also slowed to 12%.
Alphabet said its spending will “increase significantly in 2027.” Its shares fell about 9% in trading after the results.
What is free cash flow?
This is the key idea behind the whole story, so here it is in plain words.
A company earns cash from its business. It also spends cash on things that last for years, like data centres. Free cash flow is what is left after both.
If free cash flow is positive, a company is paying for its future from its own pocket. If it is negative, it is spending more than it earns, and has to use savings or borrow to fill the gap.
Earlier this year, Alphabet raised $84.8 billion from investors to help pay for its AI buildout.
Why investors changed their minds
For most of the AI boom, investors had one question: who is spending the most? Big spending was seen as a sign of strength.
Now the question is: when will this spending pay off?
The costs are enormous and growing. AI needs the most advanced computer chips, giant buildings full of servers, and huge amounts of electricity. A data centre built today may need new chips in a few years.
Investors want proof that customers will pay enough for AI services to cover that bill. Microsoft offered that proof this quarter. Alphabet offered growth, but not yet the cash.
One quarter is not the whole story
It would be wrong to say Microsoft has won the AI race, or that Alphabet’s bet is failing.
Google Cloud is growing faster than ever. Alphabet is spending now to build capacity it believes customers will need. If that demand arrives, today’s negative cash flow may look like a smart early investment.
Microsoft’s own results include a warning that some “significant investments will fail to achieve expected returns.” No company knows for sure how big the AI market will become, or how fast.
What The Lion Capital asked
The Lion Capital put questions to both companies in public posts on X on October 29. We asked Alphabet (post) when it expects its AI investment to turn cash-positive again. We asked Microsoft (post) whether its lower spending estimate reflects only delays in data centre deliveries, or a change in plans.
Neither company had responded by the time of publication.
What happens next
Amazon and Meta, the other two giants in the AI spending race, are due to report their results soon. Investors will look at the same two numbers: how much they are spending, and how much cash is left over.
The AI boom is not over. But the easy part, spending money, is done. The hard part, making it back, has begun.
By The Lion Capital Editorial Team | October 2026