A Concern for Tech ETFs Despite ‘QQQ’ Up 18% YTD?

The PowerShares QQQ (NasdaqGM: QQQ), which tracks the tech-heavy Nasdaq-100 Index, is up more than 18% year-to-date. However, some market observers are concerned about the small number of stocks driving the technology sector’s 2018 upside. Stocks such as Apple (NASDAQ: AAPL), Google parent...