Why is Powershares QQQQ outperforming the NASDAQ?

Question

Isn't it an ETF of the NASDAQ? http://finance.yahoo.com/echarts?s=QQQQ#...

This is an example over the last quarter, but you can really see it over any time frame.

Answer 1

QQQQ represents the top 100 companies (by market cap) in the Nasdaq.  It does not represent all of Nasdaq.  That's why you see a difference.

Answer 2

You're using the wrong symbol

^NDX is the symbol for the NASDAQ 100 which is what QQQQ is trying to replicate.

http://finance.yahoo.com/echarts?s=%5End...