Pearls, it is said, represent purity. They may soon stand for something else: business dynamism. In Greenville, South Carolina, two locals have created earrings that look like jewels, but contain a cluster of electronics to track body temperature, heart rate and even the wearer’s menstrual cycle. Incora Health was set up in 2022. It plans to start selling its earrings, currently in clinical trials, in a few months. “We’re first-time founders in a small city trying to change women’s health care, and that’s not lost on us,” says Theresa Gevaert, a co-founder. But the audacious young firm is part of a wave of startups that have been launched in America in the past few years. Many will fail. Some will succeed. Together they suggest change is afoot.