Losing some money is an inevitable part of investing, and there's nothing you can do to prevent it. But to be an intelligent investor, you must take responsibility for ensuring that you never lose most or all of your money.

Mathematics is ordinarily considered as producing precise and dependable results; but in the stock market the more elaborate and abstruse the mathematics the more uncertain and speculative are the conclusions we draw there from. Whenever calculus is brought in, or higher algebra, you could take it as a warning that the operator was trying to substitute theory for experience, and usually also to give to speculation the deceptive guise of investment.

The investor with a portfolio of sound stocks should expect their prices to fluctuate and should neither be concerned by sizable declines nor become excited by sizable advances. He should always remember that market quotations are there for his convenience, either to be taken advantage of or to be ignored.

... the loss of public confidence in the financial community growing out of its own conduct in recent years. I insist that more damage has been done to stock values and to the future of equities from inside Wall Street than from outside Wall Street.

A speculator gambles that a stock will go up in price because somebody else will pay even more for it.

In security analysis the prime stress is laid upon protection against untoward events. We obtain this protection by insisting upon margins of safety, or values well in excess of the price paid.

The margin of safety is always dependent on the price paid. It will be large at one price, small at some higher price, nonexistent at some still higher price.