Everyone’s Talking Bubbles. Is It Time To Act?

 | Mar 03, 2021 01:05PM ET

A leading Chinese financial official doing it too. Perhaps the only question left: Who’s not chattering, worrying and otherwise obsessing over market bubbles these days?

You may have to dig deep to find a bubble-free discussion. To be fair, the U.S. stock market appears stretched. Deciding if it’s in a bubble is another matter. Even harder: If there is a bubble, is it in imminent danger of bursting? The stock answer, as always: Maybe.

There’s plenty of intelligent things to say about market bubbles – but there’s even more dross. Let’s save you some time. Perhaps the single-most useful observation comes from Barry Ritholtz of Ritholtz Wealth Management: “Bottoms are easier to spot and harder to act on; It is easy to see a ‘false top,’ and much easier to act on it.”

Most observers agree that there’s a glut of data suggesting that if the market isn’t in a bubble, it’s certainly expensive. Or perhaps it’s safer to say the market’s not cheap. Whatever the appropriate label, the numbers speak clearly, as Bloomberg columnist John Authers helpfully points out with several charts profiling the market’s ascendance of late in relative terms.

For example, the cyclically adjusted price-earnings multiple (CAPE) designed by Professor Robert Shiller is flying high these days. “By my back-of-the-envelope calculation, the CAPE is back above 35 for only the second time in history, a figure that is hard to ignore,” Authers observes.