American Airlines (AAL) has seen a significant decline in its stock price following a downward revision of its second-quarter earnings guidance. The company now expects earnings per share (EPS) between $1 and $1.15, down from the previous range of $1.15 to $1.145. Additionally, American Airlines has revised its total revenue per available seat mile (TRASM) forecast to a decline of 5% to 6%, compared to the earlier forecast of a 1% to 3% decline. This revision is attributed to a weaker-than-expected domestic environment, according to CEO Robert Isom. As a result, AAL's stock dropped 16% in premarket trading, marking its worst day since June 2020. The broader airline sector has been affected, with other airlines like United Airlines (UAL) reaffirming their guidance but still experiencing declines in their stock prices.