Invitation Homes IPO will test investors' interest in the idea that the rental-home business can be institutionalized as apartments were before Jonathan Gray of Blackstone Group LP went on the biggest homebuying spree in history after the U.S. foreclosure crisis, purchasing repossessed properties from the courthouse steps and through online auctions. Four years, $ 10 billion and roughly 50,000 homes later, he will find out if his gambit will pay off.
