David Cordani

When Cordani isn’t busy competing in a reported 125 triathlons, he runs his company like a dedicated athlete. Since his appointment as CEO of the health insurer at the start of 2010 (he’s been with the company for decades), Cigna’s size has doubled, its customer base is up 16%, and its stock has climbed about 30% a year. In 2015, he led Cigna into a mega-merger with rival Anthem during a wave of healthcare mergers and acquisition. If approved by regulators, the proposed $54 billion deal would create the largest U.S. health insurer by membership and reduce the industry’s consolidation from five national players to three.