The modern investment bank is seldom organized in the form of a corporation, but rather as a partnership including from two to twenty members. In addition, large commercial banks have either opened bond departments or have organized separate companies which perform all the functions of investment houses.

The investment bank may emphasize certain features of its business more than others, and so its organization varies accordingly. It usually includes buying, selling, statistics and treasury departments. The function of the buying department is to investigate the various proposals submitted by corporations or other investment houses and to buy the securities if conditions warrant such action. The buying departments of large investment houses usually maintain close contact with industries in which they are interested. Also a large firm keeps itself informed through traveling representatives, who report conditions in these enterprises.

After the securities are purchased they are turned over to the selling department. This is headed by a general sales manager, who directs the work of salesmen and, at times, the operation of the branch offices. The majority of sales are made by representatives who travel through the territory allotted to them, build up a regular clientele, and thus dispose of new issues of securities. Each salesman keeps in touch with the home office and reports regularly to the sales manager. If a salesman shows ability he is frequently placed in charge of a branch office and is allowed to participate in the profits of the business.

The sales force receives considerable assistance from the statistical department, which compiles lists of customers, securities already purchased by them, and their preferences in investments. The department aids in conducting a sales campaign by preparing circulars and press notices. This department also answers customers' inquiries for information on investments. Another important task of the statistical department is to analyze proposals submitted to the consideration of the investment house.

The treasury department is concerned with such fiscal affairs as the securing of loans from banks and the carrying of accounts of customers who purchase securities on a marginal basis or on an installment plan.