(Extracted from The Intelligent Investor by Benjamin Graham)
If most secondary issues tend normally to be undervalued, what reason has the investor to believe that he can profit from such a situation? For if it persists indefinitely, will he not always be in the same market position as when he bought the issue? The answer here is somewhat complicated. Substantial profits from the purchase of secondary companies at bargain prices arise in a variety of ways. First, the dividend return is relatively high. Second, the reinvested earnings are substantial in relation to the price paid and will ultimately affect the price. In a five-to seven-year period these advantages can bulk quite large in a well-selected list. Third, a bull market is ordinarily most generous to low-priced issues; thus it tends to raise the typical bargain issue to at least a reasonable level. Fourth, even during relatively featureless market periods a continuous process of price adjustment goes on, under which secondary issues that were undervalued may rise at least to the normal level for their type of security. Fifth, the specific factors that in many cases made for a disappointing record of earnings may be corrected by the advent of new conditions, or the adoption of new policies, or by a change in management. An important new factor in recent years has been the acquisition of smaller companies by larger ones, usually as part of a diversification program. In these cases the consideration paid has almost always been relatively generous, and much in excess of the bargain levels existing not long before.