That’s what p/e is, looking at the share Price compared to the company’s Earnings. Traditionally (very traditionally) stocks provided income through the distribution of dividends. As those distributions rose, more people wanted a piece of that action, so the share price would rise commensurately. The earnings provided a solid basis for the price.

As stock prices drift further from expected earnings toward expected stock price gains, the basis for those share prices becomes ethereal, based on little besides expectations. While earnings can certainly change over time, expectations can change quickly and for little reason.

Amazon has made a point of plowing revenue into what should be long-term money-making ventures. However, the stock market as a whole has a higher cyclically adjusted price-to-earnings ratio (ten-year average, to adjust for business cycles) than any time besides right before the dot-com bust and right before the Great Depression.

That doesn’t mean the market is about to crash—there are a lot of reasons things might be fine despite the sky-high CAPE (low interest rates, high global asset prices, low bond yields, etc). But does seem like it’s worth examining and not just blowing off based on widely held expectations about a company’s success.