A list of underwriting participations by all banks in the investment banking industry. It provides rankings of investment banks in a specific business (e.g., on the basis of the proceeds of the deals they managed globally in a given year). This list is used as a basis for comparing underwriting capabilities of investment banks. It is published periodically- quarterly, semiannually, etc- to show the market share of banks and investment banks in key areas such as bookrunning underwriting and merger advisory mandates. The rankings set out in league tables are usually used by financial firms to measure their market shares and relative performance. For instance, a bookrunner is given full credit for the overall proceeds of an initial public offering (IPO), regardless of the percentage actually underwritten by the bookrunning bank (the proceeds are divided by the number of bookrunners).

Typically, there is a league table for every different type of security and geographic region.