It's almost impossible to predict when a stock is going to make a huge move. But if you own shares of MSC Industrial (NYSE:MSM)Aerojet Rocketdyne (NYSE:AJRD), or PriceSmart (NASDAQ:PSMT), you'd do well to prepare yourself for potential volatility. That's because relatively high percentages of all three companies' shares have been sold short (meaning that traders are betting against the companies and believe that share prices will go down), and all three are expected to report earnings during the upcoming week.

When the two forces of short selling and earnings reports combine, big swings are almost always the result. The two stocks I singled out earlier this month, for instance, moved an average of 6% following their respective earnings releases.

Instead of getting stressed out by this prospect, I encourage investors to check out the slideshow below to sift through the noise and figure out what's really worth paying attention to over the long run.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.