Talk about a mood-altering drug. All three of the tech companies reporting fourth-quarter numbers this afternoon—Amazon, Snap and Pinterest—had some good news to deliver. The result was a dramatic change in mood on Wall Street. For hours tech stocks had been hammered, thanks to Meta Platforms’ downbeat report on Wednesday night. But stocks reversed in after-hours trading—Snap shares leapt by an astounding 56%, after dropping 24% during regular trading. This is not a market for anyone who doesn’t like volatility.

In truth, only Snap could be said to have delivered truly strong earnings. The company reported revenue growth of 42%, well ahead of its own projections, thanks partly to what it said was a faster than expected recovery from the impact of Apple’s ad-tracking changes. Hmmm…what’s Evan Spiegel doing differently from his rival Mark Zuckerberg? Meta, after all, bemoaned Apple’s changes, claiming they would erode its revenue this year by $10 billion—the equivalent of 8% of 2021 revenues. Snap also projected 37% revenue growth in the first quarter, a somewhat healthier growth rate than Meta’s 3% to 11% projection. (For a look at Snap’s workarounds to deal with Apple’s changes, see this detailed report we published in December.)