The truly disruptive technical advances of the past decades, the PC and the internet, had something in common. They wasted a newly cheap resource—computing power and bandwidth, respectively—to do something radically new. Digital tokens and blockchains, two distinct but complementary technologies, waste cheap storage to give data the continuity of real-world assets. Bitcoin is just the first application. The technologies are far from mature, but if scalability limitations are overcome, they will have long-term disruptive potential in complex transaction networks such as trade, health care, and the Internet of Things. And it is by no means obvious that traditional intermediaries will be able to control them.