The snow is falling heavily in Stockholm, but inside a small, pitch-dark auditorium, the atmosphere is cozy and warm. A buzz of anticipation gives the space the feel of a music club as about 300 people wait for the headline act. When a tall man strides up on stage in a Palm Angels flannel shirt and black lace-up boots, he looks in fact like he might pick up an electric guitar and play for the crowd.
That would be apt: Sebastian Siemiatkowski is a rock star to many of the tech execs and investors attending this daylong conference on startups. The CEO and cofounder of Klarna—the $6.7 billion-valuation, buy-now-pay-later company—helped invent a new industry in his early 20s, built his company to become Europe’s most valuable startup, and more recently made it a player in the biggest market in the world: The U.S.
