“The spectator’s chief enemies are always boring from within. It is inseparable from human nature to hope and to fear. In speculation when the market goes against you, you hope that every day will be the last day and you lose more than you should had you not listened to hope. And when the market goes your way you become fearful that the next day will take away your profit, and you get out too soon. Fear keeps you from making as much money as you ought to. The successful trader has to fight these two deep-seated instincts. He has to reverse what you might call his natural impulses. Instead of hoping he must fear; instead of fearing he must hope. He must fear that his loss may develop into a much bigger loss, and hope that his profit may become a big profit.”
Jesse Livermore

“Every decade has its characteristic folly, but the basic cause is the same: people persist in believing that what has happened in the recent past will go on happening into the indefinite future, even while the ground is shifting under their feet.”
George J. Church

“What feels good is often the wrong thing to do.”
William Eckhardt