In early 2018, Amos Meiri got the kind of windfall many startup founders only dream of. Meiri’s company, Colu, develops digital currencies for cities—coupons, essentially, that encourage people to spend their money locally. The company was having some success with pilot projects in the UK and Israel, but Meiri had an idea for something bigger. He envisioned a global network of city currencies, linked together using blockchain technology.

Get in-depth coverage of current and future trends in technology, and how they are shaping business, entertainment, communications, science, politics, and society.