As already indicated, the types of investment banks considered perform in general one or more of the following functions: (1) investigating proposals, (2) forming syndicates for underwriting, (3) selling securities. In addition, investment houses may render the public such services as advice in selecting securities, information to customers, and protection in case of failure of the corporation issuing the securities. These functions are exercised by the several classes of investment banks to a degree varying with their size or special interest. In considering the nature of these functions no particular type of organization will be kept in mind, but, instead, the discussion will apply to all types.