BOSTON ( TheStreet) -- Shares of InterMune ( ITMN) are up almost 180% since last Friday. For investors who owned the drug company's stock last week, that means their investment more than doubled in value in just four trading sessions.Only in biotech can such volatility generate huge windfalls for investors -- those armed with a simple calendar of stock-moving events. FDA advisory panels (in the case of InterMune), drug approval decision dates and clinical trial results move biotech stocks -- a lot. Keeping close tabs on these stock-moving events is an essential task for every successful biotech investor. Not all biotech stocks rocket like InterMune. Some crash to earth like Medivation ( MDVN), which lost 70% of its value after the failure of pivotal phase III drug study. But even here, investors who knew approximately when the Medivation data were to be released could have booked profits in advance or used options to hedge their investment and cushion the blow from a bad outcome. Either way, investors caught unaware by the timing of biotech events either miss a moneymaking opportunity or get blindsided by a blowup. Here are ten biotech and drug companies with stock-moving events in the next few months. Some of these stocks might be the next InterMune; others might end up more like Medivation. Either way, it pays to keep a biotech events calendar handy.