This is a factor of prime importance in present-day investing, and it has received less attention than it deserves. The whole structure of stock-market quotations contains a built-in contradiction. The better a company’s record and prospects, the less relationship the price of its shares will have to their book value. But the greater the premium above book value, the less certain the basis of determining its intrinsic value―i.e., the more this “value” will depend on the changing moods and measurements of the stock market. Thus we reach the final paradox, that the more successful the company, the greater are likely to be the fluctuations in the price of its shares. This really means that, in a very real sense, the better the quality of a common stock, the more speculative it is likely to be―at least as compared with the unspectacular middle-grade issues.
―The Intelligent Investor, Chapter 8