The Market is More than Three Numbers

When you hear and read financial news, you likely get reports on the Dow, the S&P 500, and the NASDAQ.  These are indexes that track particular segments of the stock market.

They don't track the whole market, though.  More than 9,000 stocks are traded in the United States stock market.  The Dow Jones Industrial Average is limited to thirty very large companies.  The Standard & Poor's 500 tracks five hundred large cap companies.  The NASDAQ Composite tracks the stocks that trade on the NASDAQ stock exchange, but that only covers about a third of all the stocks and they are often more technology focused.

For a more complete picture, you should also pay attention to other indexes.  Check out the S&P 400 (a mid cap index) and the S&P 600 (a small cap index), for example.  The Russell Investment Group also has a set of indexes, as do other organizations.  Here is a good list of United States indexes.  You'll see on that Wikipedia page that many countries have their own indexes.