It’s a dilemma for many investors: you want to have cash set aside to hop on investment opportunities that might arise, but you also don’t want the money sitting in your portfolio not collecting any return. Enter cash exchange-traded funds. Experts say there is increasing demand for cash ETFs among investors old and young as they offer the flexibility of having liquid assets coupled with the benefit of a modest return.Chris Merrick, founder and owner of Merrick Financial, said there