What happened
Since the start of the pandemic, airline stocks have tended to move together, going up and down more due to macro issues like travel demand and the price of oil instead of company-specific news. But American Airlines Group (AAL -2.00%) is an outlier today, down as much as 5% even as rivals Delta Air Lines and United Airlines Holdings are basically flat.
The reason is likely the potential blowback from a transaction that does not directly involve…