Load up on stocks when they’re cheap. Reduce stocks when they’re expensive. It’s really quite simple.
Valuations tell us how expensive or cheap stocks may be, but beware! There are many different measures of valuation so it’s important to focus only on those that are highly correlated to future returns.
Below is a chart showing one measure of market valuations going back to 1900. This particular valuation metric is called the Shiller Price / Earnings Ratio, or “Shiller PE” for short. The Shiller PE has about a 90% correlation with future 10-year returns. That’s a very respectable correlation and indicates reliability.
Notice the peaks and valleys? I was curious to know how the market performed following various extremes over time to see if the Shiller PE provides useful information. So I performed a brief study. Check out the results…