Stocks are traded primarily traded on nine stock exchanges in the United States. The largest stock exchange is the New York Stock Exchange (NYSE) which lists about 2800 companies with more than 350 billion shares issued and a market value of about $13.5 trillion. A much smaller version of the NYSE is the American Stock Exchange (AMEX), which is located in Manhattan's financial district. The NYSE and AMEX are considered national exchanges. Common stocks are also traded on five major regional exchanges. The stocks of the largest companies are traded on the NYSE, whereas many smaller companies are traded on the AMEX. The regional exchanges trade stocks of local corporations in addition to stocks listed on the NYSE and AMEX.

The NYSE dates back to 1817, when brokers adopted a constitution creating the New York Stock and Exchange Board, the predecessor of toady's 'Big Board'. The constitution outlined membership requirements and commission rates and established procedures for trading and settling transactions. The brokers met in what was called a 'call' market. Two times a day the president of the board read the list of securities and members shouted bids and offers from their assigned chairs. Thus, the origin of the 'seat,' which continues to signify membership on the NYSE. The number of shares listed and the number of shares traded on the exchange have increased steadily through the years. The requirements for listing on the NYSE are more stringent than the requirements on the other exchanges. A company must meet or exceed the specified levels of net earnings, assets, and trading volume, and its shares must be widely held by investors.

The AMEX was started by a group of individuals traded unlisted shares at an outdoor location known as the Outdoor Curb Market. AMEX companies are smaller and younger than the companies listed on the NYSE. These companies frequently are considered emerging growth companies. Another characteristic of the AMEX is number of smaller companies enlisted; the speculative nature of these stocks tends to make the AMEX more volatile than the NYSE. Trading volume on the AMEX is about 3% to 5% of the NYSE.

Originally regional exchanges traded the securities of the regional companies located in their area - thus, the origin of the name. However the deployment of rapid communication expanded their scope. As a result stocks on the NYSE and AMEX as local stocks are traded. For example, IBM and General Motors are both listed on the NYSE, but are also listed on several regional exchanges. This listing permits local brokerage firms that are not members of the NYSE to trade shares of dual listed stock using membership on a regional exchange. As a result, the local broker does not have to forgo part of the commission by trading on the NYSE. Most of the volume on regional exchanges currently results from trading in dual listed issues.

The largest of the regional exchanges is the Chicago Stock Exchange. This exchange is the result of the merger of the Chicago, Cleveland, Minneapolis-St. Paul, St. Louis and New Orleans Stock Exchanges. Its trading activity now exceeds that of the AMEX, making it the second largest organized stock exchange in the United States.