Pentair plc's (NYSE:PNR) price-to-earnings (or "P/E") ratio of 21x might make it look like a sell right now compared to the market in the United States, where around half of the companies have P/E ratios below 17x and even P/E's below 9x are quite common. Nonetheless, we'd need to dig a little deeper to determine if there is a rational basis for the elevated P/E.

Pentair certainly has been doing a good job lately as its earnings growth has been positive while most other companies have been seeing their earnings go backwards. The P/E is probably high because investors think the company will continue to navigate the broader market headwinds better than most. You'd really hope so, otherwise you're paying a pretty hefty price for no particular reason.

If you'd like to see what analysts are forecasting going forward, you should check out our free report on Pentair.

What Are Growth Metrics Telling Us About The High P/E?

In order to justify its P/E ratio, Pentair would need to produce impressive growth in excess of the market.

If we review the last year of earnings growth, the company posted a terrific increase of 27%. The latest three year period has also seen an excellent 51% overall rise in EPS, aided by its short-term performance. Accordingly, shareholders would have probably welcomed those medium-term rates of earnings growth.

Shifting to the future, estimates from the analysts covering the company suggest earnings should grow by 11% per year over the next three years. That's shaping up to be similar to the 10% per annum growth forecast for the broader market.

With this information, we find it interesting that Pentair is trading at a high P/E compared to the market. It seems most investors are ignoring the fairly average growth expectations and are willing to pay up for exposure to the stock. Although, additional gains will be difficult to achieve as this level of earnings growth is likely to weigh down the share price eventually.

What We Can Learn From Pentair's P/E?

While the price-to-earnings ratio shouldn't be the defining factor in whether you buy a stock or not, it's quite a capable barometer of earnings expectations.

Our examination of Pentair's analyst forecasts revealed that its market-matching earnings outlook isn't impacting its high P/E as much as we would have predicted. When we see an average earnings outlook with market-like growth, we suspect the share price is at risk of declining, sending the high P/E lower. This places shareholders' investments at risk and potential investors in danger of paying an unnecessary premium.

Having said that, be aware Pentair is showing 1 warning sign in our investment analysis, you should know about.

If these risks are making you reconsider your opinion on Pentair, explore our interactive list of high quality stocks to get an idea of what else is out there.

Have feedback on this article? Concerned about the content? Get in touch with us directly. Alternatively, email editorial-team (at) simplywallst.com.
This article by Simply Wall St is general in nature. We provide commentary based on historical data and analyst forecasts only using an unbiased methodology and our articles are not intended to be financial advice. It does not constitute a recommendation to buy or sell any stock, and does not take account of your objectives, or your financial situation. We aim to bring you long-term focused analysis driven by fundamental data. Note that our analysis may not factor in the latest price-sensitive company announcements or qualitative material. Simply Wall St has no position in any stocks mentioned.