Definition of QQQ:

  1. An exchange-traded fund, formerly call the NASDAQ-100 Index Tracking Stock, that invests primarily in the 100 stocks that comprise the NASDAQ-100 Index. The 100 stocks in the index consist of the largest domestic and international companies, based on market capitalization, listed on the NASDAQ exchange. Also called PowerShares QQQ.

Meaning of QQQ & QQQ Definition