Remember, outflows from QQQ and modest inflows to rivals ETFs come as the Nasdaq Composite and the Nasdaq-100 trade at valuations that are well below the height of the do-com bubble.

During the last 10 years, NDX has traded at an average P/E multiple 30% greater than the S&P 500, but it currently trades at just an 8% premium (18.8x vs. 17.5x),” said Goldman Sachs strategist David Kostin in a note posted by Ben Levisohn of Barron’s last month.

Then there is earnings growth. Goldman expects Nasdaq-100 EPS of 15% over the next year compared to just 5% for the S&P 500.

Powershares QQQ

Tom Lydon’s clients own shares of Apple and QQQ.