Having historically been avoided by institutional financial investors, U.S. single-family housing—that is, free-standing residential property—received large investment inflows after the global financial crisis of 2007-2009 to rapidly become a substantial asset class. Why? And why then? The materialization of an unprecedented investment opportunity—large stocks of cheap, favorably located urban housing—was certainly pivotal. But the attractiveness of that opportunity was enhanced by a series of parallel and (for investors) propitious historical shifts in four key realms: technology, finance, housing supply, and ideas. In short, the investment transformation that occurred was “overdetermined.” The article develops this argument with a focus on investment by the firm that led the way: the Blackstone Group.