A big question in a lead up to the 2020 presidential election is whether the U.S. should move from its current insurance system-driven health care model to a single-payer concept. Multiple Democratic candidates for president as well as new arrivals on Capitol Hill have pushed for a version of single-payer or Medicare-for-All. Health insurer stocks took a tumble when a Medicare-for-All bill was introduced, making it clear investors, fearing for insurance companies’ revenues, weren’t fans.