stocks and bonds traded on an organized security exchange such as the NEW YORK STOCK EXCHANGE (NYSE) and the American Stock Exchange (AMEX). They are distinguished from unlisted securities, which are traded in the OVER-THE-COUNTER (OTC) MARKET. The organized exchanges have certain requirements that firms must meet before their stock can be listed. Among the requirements are size of the company, number of years in business, earnings record, number of shares outstanding, and market value of shares.