Graham and Dodd
From Security Analysis, 1940 edition:
“These intricacies of corporate accounting and financial policies undoubtedly provide a broad field for the activities of the securities analyst. There are unbounded opportunities for shrewd detective work, for critical comparisons, for discovering and pointing out a state of affairs quite different from that indicated by the publicized “per-share earnings.” That this work may be of exceeding value cannot be denied. In a number of cases it will lead to a convincing conclusion that the market price is far out of line with intrinsic or comparative worth and hence to profitable action based upon this sound foundation. But it is necessary to caution the analyst against overconfidence in the practical utility of his findings. It is always good to know the truth, but it may not always be wise to act upon it, particularly in Wall Street. And it must always be remembered that the truth that the analyst uncovers is first of all not the whole truth and, secondly, not the immutable truth. The result of his study is only a more nearly correct version of the past. His information may have lost its relevance by the time he acquires it, or in any event by the time the market place is finally ready to respond to it.”
