Wall Street-backed landlords are showing a greater appetite for bad mortgages as a source for cheap property as the supply of foreclosed homes declines while housing prices continue to climb.

The companies have dominated U.S. foreclosure auctions in the last two years by buying as many as 200,000 single-family homes. Now American Homes 4 Rent, the second-biggest single-family landlord, Barry Sternlicht’s Starwood Waypoint Residential Trust and Altisource Residential Corp. are leading acquisitions of non-performing loans, or NPLs, to expand their holdings of rental properties.