Donald Mullen Jr., who helped Goldman Sachs (GS) profit from the housing crash, is giving the company and its clients a way to gain from housing. 

Mullen has raised roughly $1 billion to buy single-family homes to rent since leaving Goldman Sachs last year as head of global credit and mortgages. 

His Fundemental REO has already purchased or is close to acquiring nearly 2,500 properties through foreclosure auctions, government agencies and non-profits.