American Airlines Group Inc. has unveiled a $1 billion investment plan to expand its Miami International Airport facilities, which includes 17 new gates and upgraded passenger areas. This announcement comes as the airline faces a stock decline of around 4%, closing at $13.07, despite reporting record Q4 revenue of $14 billion. The company anticipates significant passenger revenue growth of 7-10% for the upcoming March quarter, while also targeting a reduction in total debt below $35 billion by 2027 amidst ongoing financial challenges.