It's all relative. Amex stock is the same value today as it was 4 years ago and higher than it was 5 years ago and the same as it was 10 years ago. Stocks go up and they go down. In Feb of 09 Amex stock was only 12 bucks per share. In May of '14 it was about $95. And if you go back 50 years, there has been a lot of peaks and valleys for Amex. Right now their P/E ratio is rather low and there is absolutely no sign of them going away.
Actually now might be the best time to buy Amex stock since '09.