Jesse Livermore

The speculator'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 to the same ally that is so potent a success-bringer to empire builders
and pioneers, big and little. 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. It is absolutely wrong to gamble in stocks the way the average man does.

Jesse Livermore