An activist investor with a new $1.9 billion stake in Southwest is calling for big changes at the airline

• Elliott Management has called for changes at Southwest to fix what it says is poor performance.
• Southwest's share price has plummeted over 50% in three years, to below March 2020 levels.
• The hedge fund's "Stronger Southwest" plan suggests new leadership and a review of the business model.

Southwest Airlines touts itself as the "LUV" carrier, with its two free checked bags and comedic flight crews — a strategy that revolutionized low-cost air travel and earned the carrier a 47-year profitability streak from 1973 to 2019.