Sunrun Inc. (NASDAQ:RUN) shares have continued their recent momentum with a 26% gain in the last month alone. Not all shareholders will be feeling jubilant, since the share price is still down a very disappointing 32% in the last twelve months.

Although its price has surged higher, there still wouldn't be many who think Sunrun's price-to-sales (or "P/S") ratio of 1.5x is worth a mention when the median P/S in the United States' Electrical industry is similar at about 1.8x. Although, it's not wise to simply ignore the P/S without explanation as investors may be disregarding a distinct opportunity or a costly mistake.

What Does Sunrun's Recent Performance Look Like?

Sunrun hasn't been tracking well recently as its declining revenue compares poorly to other companies, which have seen some growth in their revenues on average. It might be that many expect the dour revenue performance to strengthen positively, which has kept the P/S from falling. If not, then existing shareholders may be a little nervous about the viability of the share price.

Do Revenue Forecasts Match The P/S Ratio?

The only time you'd be comfortable seeing a P/S like Sunrun's is when the company's growth is tracking the industry closely.

Taking a look back first, the company's revenue growth last year wasn't something to get excited about as it posted a disappointing decline of 12%. Still, the latest three year period has seen an excellent 103% overall rise in revenue, in spite of its unsatisfying short-term performance. Although it's been a bumpy ride, it's still fair to say the revenue growth recently has been more than adequate for the company.

Looking ahead now, revenue is anticipated to climb by 13% each year during the coming three years according to the analysts following the company. Meanwhile, the rest of the industry is forecast to expand by 43% each year, which is noticeably more attractive.

With this information, we find it interesting that Sunrun is trading at a fairly similar P/S compared to the industry. It seems most investors are ignoring the fairly limited growth expectations and are willing to pay up for exposure to the stock. These shareholders may be setting themselves up for future disappointment if the P/S falls to levels more in line with the growth outlook.

The Bottom Line On Sunrun's P/S

Sunrun appears to be back in favour with a solid price jump bringing its P/S back in line with other companies in the industry Using the price-to-sales ratio alone to determine if you should sell your stock isn't sensible, however it can be a practical guide to the company's future prospects.

When you consider that Sunrun's revenue growth estimates are fairly muted compared to the broader industry, it's easy to see why we consider it unexpected to be trading at its current P/S ratio. When we see companies with a relatively weaker revenue outlook compared to the industry, we suspect the share price is at risk of declining, sending the moderate P/S lower. This places shareholders' investments at risk and potential investors in danger of paying an unnecessary premium.

Plus, you should also learn about these 5 warning signs we've spotted with Sunrun (including 1 which is a bit concerning).

If these risks are making you reconsider your opinion on Sunrun, 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.