Spero Therapeutics, Inc.'s (NASDAQ:SPRO) price-to-sales (or "P/S") ratio of 0.5x might make it look like a strong buy right now compared to the Biotechs industry in the United States, where around half of the companies have P/S ratios above 12.6x and even P/S above 75x are quite common. Although, it's not wise to just take the P/S at face value as there may be an explanation why it's so limited.

See our latest analysis for Spero Therapeutics

What Does Spero Therapeutics' P/S Mean For Shareholders?

Recent times have been advantageous for Spero Therapeutics as its revenues have been rising faster than most other companies. Perhaps the market is expecting future revenue performance to dive, which has kept the P/S suppressed. If you like the company, you'd be hoping this isn't the case so that you could potentially pick up some stock while it's out of favour.

Keen to find out how analysts think Spero Therapeutics' future stacks up against the industry? In that case, our free report is a great place to start.

Do Revenue Forecasts Match The Low P/S Ratio?

The only time you'd be truly comfortable seeing a P/S as depressed as Spero Therapeutics' is when the company's growth is on track to lag the industry decidedly.

Taking a look back first, we see that the company grew revenue by an impressive 118% last year. Spectacularly, three year revenue growth has ballooned by several orders of magnitude, thanks in part to the last 12 months of revenue growth. Therefore, it's fair to say the revenue growth recently has been superb for the company.

Turning to the outlook, the next three years should bring diminished returns, with revenue decreasing 34% each year as estimated by the three analysts watching the company. That's not great when the rest of the industry is expected to grow by 129% each year.

In light of this, it's understandable that Spero Therapeutics' P/S would sit below the majority of other companies. Nonetheless, there's no guarantee the P/S has reached a floor yet with revenue going in reverse. Even just maintaining these prices could be difficult to achieve as the weak outlook is weighing down the shares.

The Bottom Line On Spero Therapeutics' P/S

Generally, our preference is to limit the use of the price-to-sales ratio to establishing what the market thinks about the overall health of a company.

It's clear to see that Spero Therapeutics maintains its low P/S on the weakness of its forecast for sliding revenue, as expected. As other companies in the industry are forecasting revenue growth, Spero Therapeutics' poor outlook justifies its low P/S ratio. Unless these conditions improve, they will continue to form a barrier for the share price around these levels.

Before you settle on your opinion, we've discovered 4 warning signs for Spero Therapeutics that you should be aware of.

If you're unsure about the strength of Spero Therapeutics' business, why not explore our interactive list of stocks with solid business fundamentals for some other companies you may have missed.

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