Words of wisdom by WD Gann, quoted by George Kleinman:

"Gann actually felt that the tape (today we call it the quote screen) was there to fool traders.

"The tape moves in mysterious ways, the multitude to deceive" is the way he put it. Prices can look the weakest or strongest at the strongest or weakest times. Watching quotes all day causes you to change your mind constantly. Trade too often, and this increases your percentage of being wrong. If you get in wrong, the quotes tend to keep you in wrong longer than you should be because every tick your way renews your hopes. If you get in right and you watch the screen too closely, there will come a minor move against you that will shake you out. This move, in the long run, means nothing, and as a result, you will lose a good position."