"To the public mind, selling is never sound. It always conveys the possibility of being wrong twice: first, admitting that they’ve made a buying error; second, admitting that they might be wrong in selling out. And if the stock has actually gone up, they are tormented; should they take a profit or hold for a bigger one? That creates anxiety, and anxiety breeds mistakes. But as long as they’ve got losses, and never have to decide, they can sit back comfortably and dream instead."