SOS Limited (NYSE:SOS) shares have had a horrible month, losing 25% after a relatively good period beforehand. For any long-term shareholders, the last month ends a year to forget by locking in a 90% share price decline.

After such a large drop in price, SOS may be sending buy signals at present with its price-to-sales (or "P/S") ratio of 0.1x, considering almost half of all companies in the Professional Services industry in the United States have P/S ratios greater than 1.4x and even P/S higher than 4x aren't out of the ordinary. Nonetheless, we'd need to dig a little deeper to determine if there is a rational basis for the reduced P/S.

What Does SOS' Recent Performance Look Like?

For example, consider that SOS' financial performance has been poor lately as its revenue has been in decline. It might be that many expect the disappointing revenue performance to continue or accelerate, which has repressed the P/S. Those who are bullish on SOS will be hoping that this isn't the case so that they can pick up the stock at a lower valuation.

Want the full picture on earnings, revenue and cash flow for the company? Then our free report on SOS will help you shine a light on its historical performance.

Do Revenue Forecasts Match The Low P/S Ratio?

SOS' P/S ratio would be typical for a company that's only expected to deliver limited growth, and importantly, perform worse than the industry.

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 49%. This means it has also seen a slide in revenue over the longer-term as revenue is down 51% in total over the last three years. Therefore, it's fair to say the revenue growth recently has been undesirable for the company.

In contrast to the company, the rest of the industry is expected to grow by 7.3% over the next year, which really puts the company's recent medium-term revenue decline into perspective.

With this in mind, we understand why SOS' P/S is lower than most of its industry peers. However, we think shrinking revenues are unlikely to lead to a stable P/S over the longer term, which could set up shareholders for future disappointment. There's potential for the P/S to fall to even lower levels if the company doesn't improve its top-line growth.

What We Can Learn From SOS' P/S?

The southerly movements of SOS' shares means its P/S is now sitting at a pretty low level. 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.

It's no surprise that SOS maintains its low P/S off the back of its sliding revenue over the medium-term. Right now shareholders are accepting the low P/S as they concede future revenue probably won't provide any pleasant surprises either. Unless the recent medium-term conditions improve, they will continue to form a barrier for the share price around these levels.

It's important to make sure you look for a great company, not just the first idea you come across. So if growing profitability aligns with your idea of a great company, 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.