Bulldozer [0] was a major flop. Sounded too good to be true: 2 cores sharing the same FPU because integrated GPUs should be executing these instructions much faster anyway. Maybe it was just ahead of its time and they simply couldn't deliver
But it failed hard which coincided with Intel releasing a major winner with their last planar architecture - sandy bridge.
As a result, AMD spent years circling the drain and their stock dipped below 2 dollars. Some people made good money buying around that time.