Can Theme-Based ETFs Hack It in Portfolios?

Have you heard of HACK or CIBR? SLIM or MENU? IPAY or ITEQ? These are just some of the many niche ETFs that have been introduced in the past 2 1/2 years. They are “thinly constructed” funds that trade more like subsector rather than larger sector funds, says Todd Rosenbluth, director of ETF and Mutual Fund…