As quoted from this article,

RPX says that now, with home prices at such low levels and rents rapidly approaching all time high levels, large institutional investors are raising funds with which to purchase thousands of mostly distressed properties to convert to rentals, something which the government is facilitating as a matter of policy. "These large investors are amassing hundreds of millions to billions of dollars to deploy in the rapid acquisition of thousands of residential properties." RPX said some buying has begun but most of the capital is yet to be deployed and, when it is it will have to be done quickly so 'these investors are likely to be less price sensitive than traditional buyers."