Are Shorts Watching This Number at NuVasive?

There's no foolproof way to know the future for NuVasive (NAS: NUVA) or any other company. However, certain clues may help you see potential stumbles before they happen -- and before your stock craters as a result.

A cloudy crystal ball
In this series, we use accounts receivable (AR) and days sales outstanding (DSO) to judge a company's current health and future prospects. It's an important step in separating the pretenders from the market's best stocks. Alone, AR -- the amount of money owed the company -- and DSO -- the number of days' worth of sales owed to the company -- don't tell you much. However, by considering the trends in AR and DSO, you can sometimes get a window onto the future.

Sometimes, problems with AR or DSO simply indicate a change in the business (like an acquisition), or lax collections. However, AR that grows more quickly than revenue, or ballooning DSO, can also suggest a desperate company that's trying to boost sales by giving its customers overly generous payment terms. Alternately, it can indicate that the company sprinted to book a load of sales at the end of the quarter, like used-car dealers on the 29th of the month. (Sometimes, companies do both.)

Why might an upstanding firm like NuVasive do this? For the same reason any other company might: to make the numbers. Investors don't like revenue shortfalls, and employees don't like reporting them to their superiors.

Is NuVasive sending any potential warning signs? Take a look at the chart below, which plots revenue growth against AR growth, and DSO:

Source: S&P Capital IQ. Data is current as of last fully reported fiscal quarter. FQ = fiscal quarter.

Source: S&P Capital IQ. Data is current as of last fully reported fiscal quarter. FQ = fiscal quarter.

The standard way to calculate DSO uses average accounts receivable. I prefer to look at end-of-quarter (EOQ) receivables, but I've plotted both above.

Watching the trends
When that red line (AR growth) crosses above the green line (revenue growth), I know I need to consult the filings. Similarly, a spike in the blue bars (DSO) indicates a trend worth worrying about. As another reality check, it's reasonable to consider what a normal DSO figure might look like in this space.

Source: S&P Capital IQ. DSO calculated from average AR. Data is current as of last fully reported fiscal quarter. LFQ = last fiscal quarter. Dollar figures in millions.

Differences in business models can generate variations in DSO, so don't consider this the final word -- just a way to add some context to the numbers. But let's get back to our original question: Will NuVasive miss its numbers in the next quarter or two?

The numbers don't paint a clear picture. For the last fully reported fiscal quarter, NuVasive's year-over-year revenue grew 11.2%, and its AR grew 18%. That looks OK. End-of-quarter DSO increased 6.2% over the prior-year quarter. It was up 0.4% versus the prior quarter. Still, I'm no fortuneteller, and these are just numbers. Investors putting their money on the line always need to dig into the filings for the root causes and draw their own conclusions.

What now?
I use this kind of analysis to figure out which investments I need to watch more closely as I hunt the market's best returns. However, some investors actively seek out companies on the wrong side of AR trends in order to sell them short, profiting when they eventually fall. Which way would you play this one? Let us know in the comments below, or keep up with the stocks mentioned in this article by tracking them in our free watchlist service, My Watchlist.

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At the time thisarticle was published Seth Jaysonhad no position in any company mentioned here at the time of publication. You can view hisstock holdings. He is the co-advisor ofMotley Fool Hidden Gems, which provides new small-cap ideas every month, backed by a real-money portfolio.Motley Fool newsletter serviceshave recommended buying shares of Stryker. Try any of our Foolish newsletter servicesfree for 30 days. We Fools don't all hold the same opinions, but we all believe thatconsidering a diverse range of insightsmakes us better investors. The Motley Fool has adisclosure policy.

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