A potential pullback by Microsoft on spending and datacenter construction raises questions about whether the company — one of the frontrunners among Big Tech in AI — is growing cautious about the outlook for demand.

Read More Is Microsoft taking its foot off the AI accelerator?

"It’s refreshing to see a tech CEO like Satya Nadella nerding out about the potential of quantum computing, after years of hearing Apple CEO Tim Cook talking breathlessly about infinitesimal improvements in each new iPhone."

Read More The Information: Apple is Living in the Past