It was widely deemed a temporary play: Large-scale investors buying thousands of discounted foreclosed properties during the worst of the housing crash and turning them into single-family rentals. When home prices recovered, they would surely sell them for a hefty profit. The housing market is recovering, albeit more slowly than expected. Foreclosure volume is way down and home prices are way up, but these investors are not selling.
They are buying more, and now they are buying new.