Alphabet, Amazon, Meta, and Microsoft all beat first-quarter earnings expectations on Wednesday, but investors are poised to closely scrutinize their heavy spending on AI.

Big Tech has propped up the US stock market — and in many ways, the US economy writ large — in the last year, but investors have grown anxious over whether the companies can justify their sky-high expenditures.

A report this week on OpenAI’s missed revenue and user targets added to the jitters.

Meta’s stock fell in after-hours trading Wednesday after it announced plans to put more capital toward AI.

The other three Big Tech firms reported strong cloud computing growth.