Some men have a foolish habit of telling their business secrets. If they make money they like to tell their neighbors how it was done. Nothing is gained by this, and often times much is lost. Say nothing about your profits, your hopes, your expectations, your intentions. And this should apply to letters as well as to conversation.
Business men must write letters, but they should be careful what they put in them. If you are losing money, be especially cautious and not tell of it, or you will lose your reputation.