Elliott Investment Management called for leadership change at Southwest Airlines on Monday after reporting a stake worth about $1.9 billion in the US carrier.Southwest’s shares rose more than 7% on Monday.The activist investment management firm said Southwest’s “poor execution” and its leadership’s “stubborn unwillingness” to evolve the company’s strategy have led to deeply disappointing results for shareholders, employees and customers. 3 Activist investor Elliott Investment Management blasted Southwest’ ...