A word of caution may not be amiss, however, in regard to too readily selling a common stock in the hope of switching these funds into a still better one. There is always the risk that some major element in the picture has been misjudged. If this happens, the investment probably will not turn out nearly as well as anticipated. In contrast, an alert investor who has held a good stock for some time usually gets to know its less desirable as well as its more desirable characteristics. Therefore, before selling a rather satisfactory holding in order to get a still better one, there is need of the greatest care in trying to appraise accurately all elements of the situation.
At this point the critical reader has probably discerned a basic investment principle which by and large seems only to be understood by a small minority of successful investors. This is that once a stock has been properly selected and has borne the test of time, it is only occasionally that there is any reason for selling it at all. However, recommendations and comments continue to pour out of the financial community giving other types of reasons for selling outstanding common stocks.
There is another and even more costly reason why an investor should never sell out of an outstanding situation because of the possibility that an ordinary bear market may be about to occur. If the company is really a right one, the next bull market should see the stock making a new peak well above those so far attained. How is the investor to know when to buy back? Theoretically it should be after the coming decline. However, this presupposes that the investor will know when the decline will end. I have seen many investors dispose of a holding that was to show stupendous gain in the years ahead because of this fear of a coming bear market. Frequently the bear market never came and the stock went right on up. When a bear market has come, I have not seen one time in ten when the investor actually got back into the same shares before they had gone up above his selling price. Usually he either waited for them to go far lower than they actually dropped, or, when they were way down, fear of something else happening still prevented their reinstatement.
This brings us to another line of reasoning so often used to cause well-intentioned but unsophisticated investors to miss huge future profits. This is the argument that an outstanding stock has become overpriced and therefore should be sold. What is more logical than this? If a stock is overpriced, why not sell it rather than keep it?
Before reaching hasty conclusions, let us look a little bit below the surface. Just what is overpriced? What are we trying to accomplish? Any really good stock will sell and should sell at a higher ratio to current earnings than a stock with a stable rather than an expanding earning power. After all, this probability of participating in continued growth is obviously worth something. When we say that the stock is overpriced, we may mean that it is selling at an even higher ratio in relation to this expected earning power than we believe it should be. Possibly we may mean that it is selling at an even higher ratio than are other comparable stocks with similar prospects of materially increasing their future earnings.
All of this is trying to measure something with a greater degree of preciseness than is possible. The investor cannot pinpoint just how much per share a particular company will earn two years from now. He can at best judge this within such general and non-mathematical limits as “about the same,” “up moderately,” “up a lot,” or “up tremendously.” As a matter of fact, the company's top management cannot come a great deal closer than this. Either they or the investor should come pretty close in judging whether a sizable increase in average earnings is likely to occur a few years from now. But just how much increase, or the exact year in which it will occur, usually involves guessing on enough variables to make precise predictions impossible.
Under these circumstances, how can anyone say with even moderate precision just what is overpriced for an outstanding company with an unusually rapid growth rate? Suppose that instead of selling at twenty-five times earnings, as usually happens, the stock is now at thirty-five times earnings. Perhaps there are new products in the immediate future, the real economic importance of which the financial community has not yet grasped. Perhaps there are not any such products. If the growth rate is so good that in another ten years the company might well have quadrupled, is it really of such great concern whether at the moment the stock might or might not be 35 per cent overpriced? That which really matters is not to disturb a position that is going to be worth a great deal more later.