In his monumental history Debt: The First 5,000 Years, the anthropologist David Graeber accused economists of inventing “imaginary villages” as the settings for their just-so stories about the ancient origins of financial exchange. Five thousand years later, it is hard not to apply the same phrase to the strange world of cryptocurrency, a skein of imaginary communities and exchanges that claimed to be reinventing trade and commerce from first principles even as, in reality, they reinvented forms