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.
Benjamin GrahamNo matter how careful you are, the one risk no investor can ever eliminate is the risk of being wrong. Only by insisting on what Graham called the "margin of safety" - never overpaying, no matter how exciting an investment seems to be - can you minimize your odds of error.
Benjamin GrahamEvidently stockholders have forgotten more than to look at balance sheets. They have forgotten also that they are owners of a business and not merely owners of a quotation on the stock ticker. It is time, and high time, that the millions of American shareholders turned their eyes from the daily market reports long enough to give some attention to the enterprises themselves of which they are the proprietors, and which exist for their benefit and at their pleasure.
Benjamin GrahamConfronted with a challenge to distill the secret of sound investment into three words, we venture the motto, Margin of Safety.
Benjamin Graham