Despite an already strong run, Sterling Infrastructure, Inc. (NASDAQ:STRL) shares have been powering on, with a gain of 25% in the last thirty days. The annual gain comes to 201% following the latest surge, making investors sit up and take notice.

Since its price has surged higher, Sterling Infrastructure's price-to-earnings (or "P/E") ratio of 32.7x might make it look like a strong sell right now compared to the market in the United States, where around half of the companies have P/E ratios below 19x and even P/E's below 11x are quite common. Nonetheless, we'd need to dig a little deeper to determine if there is a rational basis for the highly elevated P/E.

Recent times have been advantageous for Sterling Infrastructure as its earnings have been rising faster than most other companies. It seems that many are expecting the strong earnings performance to persist, which has raised the P/E. If not, then existing shareholders might be a little nervous about the viability of the share price.

Want the full picture on analyst estimates for the company? Then our free report on Sterling Infrastructure will help you uncover what's on the horizon.

Is There Enough Growth For Sterling Infrastructure?

The only time you'd be truly comfortable seeing a P/E as steep as Sterling Infrastructure's is when the company's growth is on track to outshine the market decidedly.

Retrospectively, the last year delivered an exceptional 54% gain to the company's bottom line. Pleasingly, EPS has also lifted 196% in aggregate from three years ago, thanks to the last 12 months of growth. Accordingly, shareholders would have probably welcomed those medium-term rates of earnings growth.

Turning to the outlook, the next year should generate growth of 5.8% as estimated by the dual analysts watching the company. Meanwhile, the rest of the market is forecast to expand by 15%, which is noticeably more attractive.

With this information, we find it concerning that Sterling Infrastructure is trading at a P/E higher than the market. It seems most investors are hoping for a turnaround in the company's business prospects, but the analyst cohort is not so confident this will happen. There's a good chance these shareholders are setting themselves up for future disappointment if the P/E falls to levels more in line with the growth outlook.

What We Can Learn From Sterling Infrastructure's P/E?

Shares in Sterling Infrastructure have built up some good momentum lately, which has really inflated its P/E. We'd say the price-to-earnings ratio's power isn't primarily as a valuation instrument but rather to gauge current investor sentiment and future expectations.

We've established that Sterling Infrastructure currently trades on a much higher than expected P/E since its forecast growth is lower than the wider market. Right now we are increasingly uncomfortable with the high P/E as the predicted future earnings aren't likely to support such positive sentiment for long. Unless these conditions improve markedly, it's very challenging to accept these prices as being reasonable.

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

It's important to make sure you look for a great company, not just the first idea you come across. So take a peek at this free list of interesting companies with strong recent earnings growth (and a low P/E).

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.