organized could not continue for a day without them; and at the same time this service is so widely spread over industry as a whole that the principle of diversification is introduced by the holding, for example, of shares in a single great bank to a much greater extent than any ordinary investor could hope to secure by subdivision of his investments into different industries.
This very wide spread of the net with which banking, bill-discounting and insurance sweep the waters of industry and commerce does not by any means eliminate risk. Those who know most about the conduct of these enterprises will acknowledge most readily that it is very easy to make mistakes in carrying them on; but if investment is confined to the shares of the large and well-established companies, then the vast resources handled, the great body of tradition and experience at the disposal of those who manage them, and the inevitable demand for their services by trade as a whole, whatever may be the fluctuations in the fortunes of its various branches, give a solidity and stability to their earning power such as no form of purely industrial investment can rival.
Competition among them is keen, but the position of the leading companies is so firmly established that there seems to be little likeli-
