Activist hedge fund Elliott Management has amassed a $1.9 billion stake in Southwest Airlines and plans to push for leadership changes at the airline that has lagged big rivals.

The stake makes Elliott one of Southwest’s largest shareholders, according to FactSet. Shares of Southwest were up 7% in premarket trading Monday.

The company had a market capitalization of $16.6 billion as of Friday’s close.

Southwest has struggled with delays at Boeing of new 737 Max planes, the newest models of the plane which the carrier exclusively flies, as well as shifting travel demand patterns after the pandemic.

The airline’s leaders are now looking for new ways to drum up revenue to better compete with rivals that offer travelers more perks and products. Southwest CEO Bob Jordan, who took the helm in February 2022 after decades with the airline, told CNBC in April that the carrier is considering ditching its single class of airplane seating and longtime boarding method.