NEW YORK (ETF Expert) -- What exactly makes an exchange-traded fund in a given economic segment "cheap?" I am beginning to think that the concept is as arbitrary and as disobliging as the automatic spending cuts in Washington D.C.For example, Russ Koesterich is the chief investment strategist for BlackRock ( BLK). I genuinely enjoy reading his perspectives on "everything iShares." Indeed, every exchange-traded fund enthusiast should follow Russ on Twitter or sign up for BlackRock's weekly update. That said, in a blog post Thursday, Russ declared that the energy and technology sectors look like bargains. The implication? One should consider investing in the iShares DJ Energy Sector Fund ( IYE) and/or the iShares DJ Technology Sector Fund ( IYW). Year-to-date, both IYE and IYW have underperformed non-cyclical segments like health care and consumer staples. Is this a contributing factor for declaring that IYE and IYW are inexpensive?