Investing can be a gut-wrenching experience if you aren't prepared, and that's going to be especially true this week if you hold shares of GT Advanced Technologies (OTC:GTATQ)Capstone Turbine (NASDAQ:CPST), or Clean Energy Fuels (NASDAQ:CLNE). That's because all three of these stocks are reporting earnings this week, and all three have lots of investors shorting their respective stocks.

When these two forces come together, volatility is almost always the result. The last time I forecast volatility based on these two variables, the stocks I singled out moved an average of 8% following their quarterly reports.

Trying to use this information to time the market would be extremely hazardous, as there's no telling whether a stock's swing will be up or down. Instead, it's important to ignore the noise and focus on what really matters if you own one of these three stocks.

In the slideshow below, I'll explain -- in as simple of terms as possible -- why so many are betting against these companies and what long-term investors will really be keeping their eyes on.