We're used to thinking of high-tech innovation and startups as generated and clustered predominantly in fertile US ecosystems, such as Silicon Valley, Seattle, and New York. But as with so many aspects of American economic ingenuity, high-tech startups have now gone truly global. The past decade or so has seen the dramatic growth of startup ecosystems around the world, from Shanghai and Beijing to Mumbai and Bangalore, not to mention London, Berlin, Stockholm, and Toronto. A number of US regions continue to dominate the global landscape—including the San Francisco Bay Area, New York, Boston, and Los Angeles—but the rest of the world is rapidly gaining ground.