Yea, I don't think you know how the stock market works.
The stock market tends to focus on metrics such as customer retention and year-over-year revenue growth, not just profitability, pricing stocks accordingly . On AMEX’s current trajectory they are likely going to start alienating some of their customer base, resulting in some customers shifting their business to other banks. If this happens Amex’s financials will be negatively impacted and would be reflected in the stock price going forward.