And add to that some basic fundamentals to understand why the volatility is so high with EXP. Over 70% of EXP is held by institutions which means less than 30% of outstanding shares are available for folks like you and me. Then look at the shear size of short positions held on EXP. When the big mutual funds start unloading their positions, you can indeed expect the price to fall quickly on this stock. You can check this basic information by clicking on "Key statistics" under "Company" in Yahoo Finance for example.