While much of the energy sector struggled with faltering oil prices, the U.S.’s largest independent refiner eked out gains by processing crude into industrial products.That pushed up revenue 28.4% in 2019 even as net income remained flat. Still, the Ohio-based business had a tumultuous year. It purchased Andeavor, a move that expanded its reach as a refiner, but failed to live up to Marathon's expectations. Activist investors, meanwhile, renewed demands for a management shakeup. They also pushed for a review of the company's pipeline and storage operations, as well as the planned spin-off of its retail Speedway business. Amid the turmoil, the company’s long-time CEO plans to retire this year.