The Nasdaq, the Dow Jones Industrial Average and the S&P 500 are all ways to see just how well publicly-traded stocks are doing over any particular time. They’re called stock indexes, and they all view the stocks slightly differently. These indexes measure the performance of a group of stocks that are considered reflective of the broad economy and market.
So: Nasdaq has more than 3,000 stocks listed, and is known for featuring big technology, like Microsoft, and biotech companies. The Dow includes 30 huge stocks, think Apple, and was created about 120 years ago. Standard & Poor’s 500 Index is composed of 500 of the largest companies publicly traded in the U.S. Of these three indexes, the S&P 500 is considered to be the best representation of the U.S. stock market as a whole.