In the face of the current highly ebullient stock market, close watchers of valuation metrics are frequently dismissed as ignoring the prospect for accelerating GDP growth and lower corporate tax expense, but I will step onto that turf anyway. It may make me look foolish, as Warren Buffett recently played down concerns about the market's valuation, even though his often-preferred metric in years past (total stock market value relative to annual GDP) is dangerously high, but that's okay.
Here is a look at my preferred valuation metric; a variant of the P/E ratio that uses "peak earnings" (the highest level of corporate profits ever produced in a 12 month period) instead of trailing 12 month earnings (impacted solely by the current economic environment) or forward earnings estimates (usually overly optimistic). We'll go back more than 50 years, not only to get an idea of historical trends, but also because that is the data I have.
When people ask me about my view of the market, I tend to give a tempered response because it is hard to argue that we should really get any earnings multiple expansion. After all, we now sit above 20 times "peak earnings" and that has only happened once in the last 55 years. As you can see, that one time (the dot-com bubble of the late 1990's) is not exactly a time we probably want to emulate this time around.
It is important to note that high valuations do not guarantee poor future returns. There is a high correlation, but you can map out mathematical scenarios whereby P/E ratios mean-revert and stock prices don't crater. Simply put, it requires extraordinary earnings growth that can more than offset a decline in P/E ratios (which we should expect if interest rates continue to increase). Right now the U.S. market is banking on this outcome, so earnings and interest rates are probably the most important things to watch in coming quarters and years when trying to gauge where the market might go from here.
Author's note: The use of "peak earnings" is not common, so it is worth offering a brief explanation for why I prefer that metric. Essentially, it adjusts for recessions, which are temporary events. If investors use depressed earnings figures when they value the market, they might conclude stocks are not undervalued even if prices have declined materially. This is because they inherently assume that earnings will stay low, even though recessions typically last only 6-12 months and end fairly abruptly.
As an example, let's consider the 2008 recession. The S&P 500 fell 38% that year, from 1468 to 903. S&P earnings fell by 40%, from ~$82 to ~$50. If we simply use trailing 12-month earnings, we see that the P/E multiple on the index was 18x at the beginning of 2008, and was also 18x at the end of the year. So were stocks no more attractively priced after a near 40% fall? Of course they were, but using traditional P/E ratios didn't make that evident.
If we instead used "peak earnings" (which were attained in 2006 at ~$88), we would have determined that the market was trading at ~17x at the outset of 2008 and had fallen to just 10x by the end of the year. By that metric, investors would have realized that stocks were a screaming buy when the S&P traded below 1,000.