Alan does not trust the stock market and very seldom invests in it. However, a few years ago, Alan purchased 100 shares of Specific Motors Corp. for $1,000. A year later, he purchased an additional 100 shares of Specific Motors Corp. for $2,000. Recently, Alan has become uncomfortable having so much money invested in the market. He decides to sell 100 shares of Specific Motors, which is currently trading at $15 a share. Has Alan realized a $500 gain or a $500 loss?