The single-family rental industry argues that institutions own only a fraction of the U.S. housing stock. : (Bloomberg) -- Conservatives looking for a fresh populist message to carry into 2022 are taking on Wall Street firms for buying up single family homes as rentals, attacking the growing practice as hurting the middle class. Blackstone Group Inc., KKR & Co. and other private-equity firms are increasingly making new investments in single-family homes to rent out, betting that the hot housing market will generate solid returns as the U.S. emerges from the coronavirus pandemic.