 Shares of Tortoise Acquisition NYSE: SHLL were trading higher on Thursday. Intense investor interest in electric vehicles has powered shares of Tortoise, a special purpose acquisition company SPAC that is preparing to merge with electric-truck drivetrain maker Hyliion, to major gains over the last few weeks. As of 3:15 p.m. EDT, Tortoises shares were up 9.6 from Wednesdays closing price. 