Definition: Somewhat the equivalent of buy and sell, however with an investing twists. If enter an order to go long 100 shares of IBM, it means you want to buy IBM. Likewise, to short IBM is to sell the stock. Long also describes your position in a stock. For example, your brokerage statement might show you were long 100 IBM, which means you own 100 shares of IBM. Your account could also show you were short 100 IBM, which means you sold 100 shares of IBM short. (See short selling).