The only reason for not doing it would be that some new situation has arisen, and this situation makes you all but certain that you can go on winning for a while. Except in such unusual circumstances, get in the habit of selling too soon. And when you’ve sold, don’t torment yourself if the winning set continues without you. In all likelihood it won’t continue long. If it does, console yourself by thinking of all the times when selling too soon preserved gains you would otherwise have lost.
