None of this means that there is no reason to be worried about the FAANG stocks.
Apple is trading like the yet-to-be-released iPhone 8 is already a huge hit. And nearly 90 percent of Amazon's valuation, at least by one analysis, is based on earnings that won't materialize until 2020 or later.
But the idea that investors are sucking more out of tech stocks than they did in the past is wrong as well.
This column does not necessarily reflect the opinion of Bloomberg LP and its owners.