Learn to take losses quickly and cleanly. There is something about inside information which seems to paralyze a man's reasoning powers. Beware of barbers, beauticians, waiters - or anyone - bringing gifts of 'inside' information or tips. Don't try to be a jack of all investment. Stick to the field you know best.
If a speculator is correct half of the time, he is hitting a good average. Even being right 3 or 4 times out of 10 should yield a person a fortune if he has the sense to cut his losses quickly on the ventures where he is wrong.
Society can progress if men's labors show a profit - if they yield more than is put in. To produce at a loss must leave less for all to share.