The fact that the forward P/E is lower than the trailing is normal, as Mark Hubert at The Wall Street Journal explains. The three main reasons:
- Corporate earnings usually increase each year.
- Analysts’ estimates use “operating earnings” — a “looser category” than the actual reported earnings used in the trailing metric.
- Wall Street analysts’ predictions tend to be overly optimistic.
“These three factors conspire to make forward-looking P/Es 24% lower on average than those based on trailing earnings,” Hulbert wrote, citing a study by Cliff Asness and Anne Casscells on the two types of P/Es using data covering nearly three decades.
And that’s why you should be sure not to compare a trailing P/E ratio to a forward one, as the metrics each tell very different stories.
Instead, the best way to use either P/E ratio is to compare it against a similarly calculated P/E ratio … say, of companies in the same industry, or the market in general.
Going back to McDonald’s, an obvious comparison would be to other fast-food chains, as seen in the table below. Just remember to compare trailing to trailing and forward to forward.
|Company||Ticker||Trailing P/E||Forward P/E|
You also can compare the stock’s P/E to its own historical valuations. While MCD’s ratios look low — meaning it has lower expected growth compared to its peers, and is often referred to as “looking cheap” — the trailing P/E actually isn’t all that great when you compare it to McDonald’s historical trailing P/E, as shown by this graph, courtesy of YCharts:
The stock’s five-year average for a trailing P/E ratio is 16.6, while the range goes from 13 — hit in October 2008 — to 19.72, which came in late 2011 amid a 30% run for MCD that year.
Right now, that means that McDonald’s looks undervalued compared to its peers, but slightly overpriced compared to its historical valuation. But why should you care?
Well, if you think McDonald’s P/E is too low, you might buy the stock based on the theory that other investors eventually will discover that company’s “true” value, driving up the price and thus “normalizing” the P/E. On the flip side, if you think it’s currently overvalued, you would avoid it on the assumption that the “true” value is lower than current prices, and that prices eventually will reflect that by heading lower.
One huge caveat, though: Some stocks always trade at a premium to the earnings they produce. Case in point, Netflix (NFLX), whose $273 price tag is a whopping 340 times the company’s trailing earnings. That’s not out of the ordinary, as the company’s average P/E over the last five years is nearing triple digits, and it even hit a high of 669 earlier this year!
Thus, trying to use this valuation tool to analyze Netflix would be like trying to use a screwdriver to tie your shoe — and this also is the case for other historically high-P/E stocks like Amazon (AMZN) and Facebook (FB).
The bottom line: Understanding price-to-earnings ratios might not be useful for every stock analysis, but it’s a fine addition to your investing toolkit.
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