The parent company of Facebook and Instagram continues to exceed expectations for ad sales. Analysts are less sure about its big swings.

Wall Street's AI heavyweights added a combined half a trillion dollars in stock market value late on Wednesday after quarterly reports from Microsoft and Meta Platforms showed massive investments in the emerging technology were paying off.

The S&P 500 rose 0.5% and is just above the record high it set on Monday. The Dow Jones Industrial Average was mostly unchanged as of 12:01 p.m. Eastern.

And both Meta and Microsoft were already on track to spend more than 30% of this year’s revenue on capital expenditures, compared with about 15% to 20% historically. Those outlays were already beginning to look like mere table stakes after Google parent Alphabet used its report last week to bump up its own capex spending plans for this year to $85 billion.