"QQQ Definition”
Definition: QQQ is the ticker symbol for the Nasdaq-100 Trust, an exchange traded fund that trades on the American Stock Exchange. By investing in the QQQ, much like an index fund, an investor gets all of the stocks that make up the Nasdaq 100 in a single security.
Also Known As:
triple q's, cubes
http://mutualfunds.about.com/cs/glossaries/g/QQQ.htm