Nasdaq 100 Index An index composed of the 100 largest, most actively traded U.S companies listed on the Nasdaq stock exchange. This index includes companies from a broad range of industries with the exception of those that operate in the financial industry, such as banks and investment companies. Investopedia Says: Individual investors are able to gain exposure to the Nasdaq 100 index by purchasing exchange-traded funds (ETFs) that are specifically designed to track its performance. The most popular of these ETFs is known as the QQQQ. Related Terms: Capitalization-Weighted Index Exchange-Traded Fund - ETF Index Nasdaq QQQQ |