In the following video, Fool contributor Matt Thalman discusses a few risks in shorting a stock. One is that while the upside potential of shorting a stock is capped at a 100% gain, the downside potential is unlimited -- the complete opposite from buying a stock outright.

Another risk is that when you short a stock, you're essentially saying management doesn't know what it's doing. But if you're shorting Hewlett-Packard (NYSE:HPQ) and Dell (UNKNOWN:DELL.DL) based on declining PC sales, and the companies' management teams deliver on their goals of diversifying their businesses and becoming less reliant on PC sales, your gamble may not pay off. 

See more in the following video.