Microsoft AI spending miss sends CoreWeave and Nebius tumbling

Shares of AI cloud infrastructure providers such as CoreWeave and Nebius fell on Thursday after Microsoft’s capital expenditures in the quarter ended September 30 came in below analysts’ expectations. The spending miss raised concerns that its partners would take longer to bring data-center capacity online, Seeking Alpha reports.

CoreWeave and Nebius were down 3% and 5%, respectively, in early U.S. trading on Thursday, while IREN plunged almost 7%. The declines followed Microsoft’s first-quarter earnings report for its fiscal 2027, in which the tech giant reported capital expenditures of $45.2 billion versus the $50.7 billion analysts had expected. Although Microsoft continues to invest heavily in AI infrastructure, with capex up 30% year over year in the latest quarter, its lower-than-expected AI spending fueled market concerns that its partners would take longer to bring data-center capacity online, Seeking Alpha writes.

In 2025, Microsoft signed a $17.4 billion agreement with Nebius for computing capacity, with options that could increase its value to around $20 billion. Microsoft is also one of CoreWeave’s largest customers, Seeking Alpha points out.

Neocloud stocks had already been under pressure over the last several weeks. Rising interest rates have heightened concerns that borrowing will become too expensive and lenders will start pulling back.

On Sunday, SpaceX CEO Elon Musk warned on X that more than 200 next-generation cloud infrastructure providers could go bankrupt. He said debt markets had almost entirely shut off access to financing for companies without substantial revenue outside of AI data centers. SpaceX itself rents AI infrastructure to Anthropic and Google.