NEW YORK — The downside of high expectations thumped Wall Street on Thursday, and Microsoft and Meta Platforms dragged U.S. stock indexes lower despite delivering strong profits for the summer.

The S&P 500 sank 1.9% for its worst day in eight weeks and fell further from its record set earlier this month. The Dow Jones Industrial Average dropped 378 points, or 0.

9%, while the Nasdaq composite tumbled 2.8% for a second straight loss after setting its latest all-time high. Microsoft reported bigger profit growth for the latest quarter than analysts expected.

Its revenue also topped forecasts, but its stock nevertheless sank 6% as investors and analysts scoured for possible disappointments. Many centered on Microsoft’s estimate for upcoming growth in its Azure cloud-computing business, which fell short of some analysts’ expectations. The parent company of Facebook, meanwhile, likewise served up a better-than-expected profit report.

As with Microsoft, that wasn’t enough to boost its stock. Investors focused instead on Meta Platforms’ warning that it expects a “significant acceleration” in spending next year as it continues to pour money into developing artificial intelligence. It fell 4.

1%. Both Microsoft and Meta Platforms have soared in recent years amid a frenzy around AI, and they’re entrenched among Wall Street’s most influential stocks. But such stellar performances have critics saying their stock prices have simply climbed too fast, leaving them too expens.