From Security Analysis, 1940 edition.
“If the analyst is convinced that a stock is worth more than he pays for it, and if he is reasonably optimistic as to the company’s future, he would regard the issue as a suitable component of a group investment in common stocks. This attack on the problem lends itself to two possible techniques. One is to buy at times when the general market is low, measured by quantitative standards of value. Presumably the purchases would then be confined to representative and fairly active issues. The other technique would be employed to discover undervalued individual common stocks, which presumably are available even when the general market is not particularly low. In either case the “margin of safety” resides in the discount at which the stock is selling below its minimum intrinsic value, as measured by the analyst. But with respect to the hazards and the psychological factors involved, the two approaches differ considerably.”
“We incline strongly to the belief that this last criterion—a price far less than value to a private owner—will constitute a sound touchstone for the discovery of true investment opportunities in common stocks. This view runs counter to the convictions and practice of most people seeking to invest in equities, including practically all the investment trusts. Their emphasis is mainly on long-term growth, prospects for the next year, or the indicated trend of the stock market itself. Undoubtedly any of these three viewpoints may be followed successfully by those especially well equipped by experience and native ability to exploit them. But we are not so sure that any of these approaches can be developed into a system or technique that can be confidently followed by everyone of sound intelligence who has studied it with care. Hence we must raise our solitary voice against the use of the term investment to characterize these methods of operating in common stocks, however profitable they may be to the truly skillful. Trading in the market, forecasting next year’s results for various businesses, selecting the best media for long-term expansion—all these have a useful place in Wall Street. But we think that the interests of investors and of Wall Street as an institution would be better served if operations based primarily on these factors were called by some other name than investment.”