Stock Analysis

# Here's What Costain Group PLC's (LON:COST) P/E Ratio Is Telling Us

•  Updated

This article is for investors who would like to improve their understanding of price to earnings ratios (P/E ratios). We'll apply a basic P/E ratio analysis to Costain Group PLC's (LON:COST), to help you decide if the stock is worth further research. Looking at earnings over the last twelve months, Costain Group has a P/E ratio of 7.67. That is equivalent to an earnings yield of about 13.0%.

See our latest analysis for Costain Group

### How Do You Calculate A P/E Ratio?

The formula for price to earnings is:

Price to Earnings Ratio = Share Price ÷ Earnings per Share (EPS)

Or for Costain Group:

P/E of 7.67 = £1.73 ÷ £0.23 (Based on the trailing twelve months to June 2019.)

### Is A High P/E Ratio Good?

A higher P/E ratio means that buyers have to pay a higher price for each £1 the company has earned over the last year. That isn't necessarily good or bad, but a high P/E implies relatively high expectations of what a company can achieve in the future.

### Does Costain Group Have A Relatively High Or Low P/E For Its Industry?

The P/E ratio indicates whether the market has higher or lower expectations of a company. If you look at the image below, you can see Costain Group has a lower P/E than the average (9.6) in the construction industry classification.

This suggests that market participants think Costain Group will underperform other companies in its industry. Many investors like to buy stocks when the market is pessimistic about their prospects. It is arguably worth checking if insiders are buying shares, because that might imply they believe the stock is undervalued.

### How Growth Rates Impact P/E Ratios

If earnings fall then in the future the 'E' will be lower. That means even if the current P/E is low, it will increase over time if the share price stays flat. A higher P/E should indicate the stock is expensive relative to others -- and that may encourage shareholders to sell.

Costain Group's earnings per share fell by 34% in the last twelve months. But EPS is up 4.1% over the last 5 years.

### A Limitation: P/E Ratios Ignore Debt and Cash In The Bank

One drawback of using a P/E ratio is that it considers market capitalization, but not the balance sheet. In other words, it does not consider any debt or cash that the company may have on the balance sheet. Theoretically, a business can improve its earnings (and produce a lower P/E in the future) by investing in growth. That means taking on debt (or spending its cash).

Such expenditure might be good or bad, in the long term, but the point here is that the balance sheet is not reflected by this ratio.

### So What Does Costain Group's Balance Sheet Tell Us?

Costain Group has net cash of UK£41m. This is fairly high at 22% of its market capitalization. That might mean balance sheet strength is important to the business, but should also help push the P/E a bit higher than it would otherwise be.

### The Verdict On Costain Group's P/E Ratio

Costain Group's P/E is 7.7 which is below average (16.8) in the GB market. The recent drop in earnings per share would make investors cautious, the relatively strong balance sheet will allow the company time to invest in growth. If it achieves that, then there's real potential that the low P/E could eventually indicate undervaluation.

Investors have an opportunity when market expectations about a stock are wrong. If it is underestimating a company, investors can make money by buying and holding the shares until the market corrects itself. So this free report on the analyst consensus forecasts could help you make a master move on this stock.

Of course you might be able to find a better stock than Costain Group. So you may wish to see this free collection of other companies that have grown earnings strongly.

We aim to bring you long-term focused research analysis driven by fundamental data. Note that our analysis may not factor in the latest price-sensitive company announcements or qualitative material.

If you spot an error that warrants correction, please contact the editor at editorial-team@simplywallst.com. This article by Simply Wall St is general in nature. It does not constitute a recommendation to buy or sell any stock, and does not take account of your objectives, or your financial situation. Simply Wall St has no position in the stocks mentioned. Thank you for reading.

#### Costain Group

Costain Group PLC provides smart infrastructure solutions for the energy, water, transportation, and defense markets in the United Kingdom.