It's Microsoft's turn to be in the investor doghouse over artificial-intelligence spending.

Three months ago, Meta Platforms (META) seemed to be Wall Street's punching bag in response to AI expenses that were potentially out of whack with AI revenue. But Meta's 7.3% stock climb in Wednesday's extended session, following the company's own earnings report, suggests investors are now more at peace with the balance between AI investments and monetization over there.

Not so with Microsoft $(MSFT)$, whose shares were off 6.7% in Wednesday's extended trading, a move that would constitute their largest post-earnings drop in more than three years if it were to hold through the close of Thursday's regular session.

Microsoft's headline results beat expectations, and Azure cloud-computing growth rose 38% in constant currency, hitting Wall Street's mark. But some investors clearly were hoping for more, especially as capital-expenditure spending soared 66% relative to a year before, hitting $37.5 billion inclusive of finance leases.

This dynamic was a hot topic on Microsoft's earnings call. "One of the core issues" dogging Microsoft investors, according to Morgan Stanley's Keith Weiss, is that spending came in higher than expected while Azure has been growing "maybe" a bit slower than hoped.

"And I think that fundamentally comes down to a concern on the ROI on this capex spend over time," he told management on the call, referring to returns on investment.

Microsoft was once viewed to be in a better spot than Meta in terms of AI monetization. Microsoft could cash in on AI spending directly, through its cloud-computing business. Meta, meanwhile, had to prove to investors that AI was paying off through better content recommendations and improved advertising targeting.

But with tight supply of chips from Nvidia (NVDA) and others, Microsoft is short on cloud capacity relative to its demand. And the company has had to make tough choices about how to allocate resources. Management suggested that if the company put more graphics processing units toward serving third parties in the cloud, that would come at the expense of internal developers who need GPUs to build other Microsoft services.

"We're really making long-term decisions," CFO Amy Hood said on the earnings call. The company wants to make sure it's "investing in the long-term nature of R&D and product innovation," a reference to research and development.

Microsoft expects 37% to 38% growth in Azure cloud-computing revenue on a constant-currency basis in the March quarter, while analysts had been modeling 37%. But Hood suggested investors should think of the company's guidance more as "allocated capacity," meaning that Microsoft presumably could be growing faster there if it chose to shift more of its limited resources in Azure's direction.

The commentary failed to stem the after-hours decline in Microsoft shares. "Even with top- and bottom-line beats, capex remains the market's central concern for hyperscalers, as trader focus shifts from growth optics to the timing and payoff of AI investment," Jake Behan, the head of capital markets at ETF provider Direxion, said in emailed comments.

He noted that Microsoft's lack of Azure upside could also underscore competitive fears.

While Amazon.com's stock (AMZN) was off fractionally in the extended session, Alphabet's $(GOOGL)$ $(GOOG)$ moved almost 2% higher, implying investors think the company might be on track for a more impressive cloud performance relative to Wall Street's expectations.