WINDERMERE, Fla. ( Stockpickr) -- Corporate insiders sell their own companies' stock for a variety of reasons. They might need the money for a big personal purchase such as a house or to fund a child's wedding. Sometimes they sell as part of a planned selling program that they have put in place for diversification purposes. Other times they sell because they think their stock is fully valued. Some dump their own stock because they're worried about the state of the economy and think shares could go down significantly.But they only buy their own shares for one reason: because they think the stock will go up substantially. The key word in that last statement is "think." Just because a corporate insider thinks his stock is going to go up, that doesn't mean it will. Insiders can have all the conviction in the world that their stock is a bargain, but if the market doesn't agree with them, it won't matter. Related: 5 Stocks With Bullish Analyst Sentiment Recently, we've had a number of companies whose corporate insiders were buying large amounts of stock. These insiders might be buying because they like the future prospects for their company. They could be loading up because the recent market volatility has created an opportunity for them to get in on the cheap. Some could be making a long-term bet by buying up their shares right now. Here's a look at a number of companies whose insiders have been loading up on their own stock recently per SEC filings. American Superconductor If there was an award given out to an insider for loving to average down on a stock, it would go to Kevin Douglas, an under-the-radar entrepreneur-turned-investor and beneficial owner of American Superconductor ( AMSC). American Semiconductor is a power technology company offering a range of technologies and solutions spanning the electric power infrastructure from generation to delivery to end use. This stock has been absolutely annihilated this year, with shares down over 53%. It has a market cap of $677.86 million and trades at a forward price-to-earnings of 19.93. The company is cash-rich, with around $242.93 million of cash on its balance sheet and zero debt.