Although there are many stock market indices, there are a few that are more regularly traded across the financial markets. Some of these indices are: The Dow Jones Industrial Average – Commonly referred to as “the Dow”, this index includes stocks of the top 30 companies in the United States in terms of size and influence. The Dow is price-weighted which means that it derives its value from the weighted average of the prices of these 30 stocks. The value of the Dow represents approximately 25% of the value of the US stock market. The S&P 500 Index – Standard and Poor’s 500 index is a portfolio of the 500 most traded stocks in the US stock market. Since the value of this index represents as much as 80% of the US stock market, it gives a good indication of the performance of the entire stock market. The S&P 500 is market-weighted rather than price-weighted. The value, therefore, depends on the market capitalization of the relevant stocks included. The Wilshire 5000 index includes stocks of almost every publicly-traded company headquartered in the USA. Because of this, it is also referred to as the “total market” index. The Nasdaq Composite Index – This index is more specialized than the others because it is comprised solely of technology stocks. It is market-weighted and includes all the stocks that are traded on the Nasdaq stock exchange. Not all stocks in the Nasdaq, are of companies that are headquartered in the US.