The extent of the tech sell-off today has been staggering, with billions of dollars wiped out from the Magnificent 7 alone in just the first two hours of trading, and trillions over the last week. Part of the reason is a fundamental story investors have been worried about – just when will the high costs of AI begin to pay off? Valuations have also re-rated since the Nasdaq hit all-time highs just a few weeks ago.