It is the market in which shares are issued and traded either through exchanges or over-the-counter markets. It promotes investment in corporate securities, providing capital for new businesses and income for investors. Some exchange members are specialists in particular types of securities, while others act as agents for other brokers. The main purpose of a stock market is to facilitate the exchange of securities between buyers and sellers.

There are two main types of stock available to the public. The common stock is owned by many investors and it is more widely available. Companies generally offer this type of stock to the public to raise money. The preferred stock represents ownership of a corporation, but it differs in several aspects.

Stocks that are handled by one or more stock exchanges are called listed stocks. Each and every exchange has its own criteria and standards. Once a company is listed, trading in its stock will be blocked if the company's financial condition devolves to the point that it no longer meets the exchange's minimum requirements. The different types of traders are scalpers, momentum traders, technical traders and fundamental traders.

There are different stock exchanges that are offering stocks for investors. Out of all these, NASDAQ is the most popular stock exchange. Other largest stock exchange in the U.S. is New York Stock Exchange (NYSE), which is formed in 1792. The activities of the stock market are closely monitored by the federal Securities and Exchange Commission to prevent the manipulation of stock prices and other activities that lessen investor confidence. The third largest exchange in the U.S. is the American Stock Exchange (AMEX). The AMEX used to be an alternative to the NYSE, but that role has since been filled by the NASDAQ.

In fact, the National Association of Securities Dealers (NASD), which is the parent of NASDAQ, bought the AMEX in 1998. Almost all trading now on the AMEX is in small-cap stocks and derivatives. There are many stock exchanges located in just about every country around the world. The two other main financial hubs are London, home of the London Stock Exchange and Hong Kong, home of the Hong Kong Stock Exchange. The OTCBB is home to penny stocks because there is little to no regulation.