QQQQ

The QQQQ is the original ticker symbol for the Nasdaq 100 Trust, an ETF that trades on the Nasdaq. This security offers broad exposure to the tech sector by tracking the Nasdaq 100 Index, which consists of the 100 largest and most actively traded non-financial stocks on the Nasdaq. It is also known as "cubes" or the "quadruple-Qs" and is now listed under the PowerShares QQQ Trust or QQQ, its current ticker symbol.

The QQQQ is now traded through the PowerShares QQQ Trust, but it still tracks the Nasdaq 100, a stock index of the 100 largest companies listed on the Nasdaq by market cap. The Nasdaq 100 index comprises companies from almost all sectors except for financial services. These non-financial sectors include retail, biotechnology, industrial, technology, health care and others. It provides a good investment choice for investors seeking exposure to the tech sector, because many of the largest companies listed on the Nasdaq are blue chip tech stocks such as Google (GOOGL), Microsoft (MSFT), and Qualcomm (QCOM).

All companies in the PowerShares QQQ Trust must be part of the Nasdaq 100 and have to be listed on the Nasdaq exchange for at least two years. Some exceptions are made for companies listed for one year but have extremely high market capitalizations. All stocks need to have an average daily trading volume of 200,000 and are required to report earnings both quarterly and annually. Companies with bankruptcy issues are omitted from the PowerShares QQQ Trust.

The PowerShares QQQ Trust is tech-heavy and has a total of 54.72% allocated to the technology sector. Consumer cyclicals are the next highest sector, with a 21.27% allocation, and the health care sector rounds out the top three with a 13.52% allocation. All other sectors have less than a 10% allocation within the PowerShares QQQ Trust, with consumer non-cyclicals, industrials and telecommunications rounding out the top six sectors represented.

It's no surprise then that eight of the PowerShares QQQ Trust's top 10 company holdings are technology firms. Notable technology holdings include Apple, Microsoft, Amazon, Google, Facebook, Intel, and Cisco. It's worth noting the PowerShares QQQ Trust tracks a limited number of stocks  compared to other Nasdaq ETFs. For example, the popular Nasdaq Composite Index (IXIC) tracks every stock listed on the Nasdaq, including financial services. The IXIC tracks more than 3,000 public companies.