Over the past two years, roughly $13 billion in securities backed by single-family rental properties have come to market, a good start for a business that barely existed five years ago. But despite that growth, there are concerns that the “easy money” could be behind the sector. Some of that concern stems from the flood of entrants into the single-family rental market – a boom that turned red hot in 2012 and 2013 when it was first revealed that institutional investors such as The Blackstone Group and others were buying thousands of properties in once decimated housing markets with an eye toward renting them out. When investors began issuing securities backed by the rent rolls, even more money began pouring...