Investment banks are essentially financial intermediaries, who primarily help businesses and governments with raising capital, corporate mergers and acquisitions, and securities trade. In USA such banks are the most important participants in the direct market by bringing financial claims for sale. They help interested parties in raising capital, whether debt or equity in the primary market to finance capital expenditure.
Once the securities are sold, investment bankers make secondary markets for the securities as brokers and dealers. In 1990, there were 2500 investment banking firms in USA doing underwriting business. About 100 firms are so large that they dominate the industry.… Read the rest