Another thing to remember about Amazon is that while their P/E is astronomical, two years ago they had never turned a profitable quarter as a company (or if they had, it was rare). Now they're turning a significant profit every quarter. If there's a company whose absurd P/E is warranted, it's probably Amazon. I'm not sure what the ceiling is on the company but it's very high. But, at some point, that P/E needs to normalize, which means the stock price will flatten. Not sure when that will happen, though.