BoomPickens Friday, 10/06/17 01:56:52 AM Re: None Post # of 2688783 What is the Nasdaq? The NASDAQ refers to two different things. First is the largest electronic stock market in the U.S. - the National Association of Securities Dealers Automated Quotation System. Second is the popular stock index called the NASDAQ Composite Index. It measures all domestic and international stocks listed on The NASDAQ, which number over 3,000. It was started in 1971 and is now one of the most important stock indexes.