Wells Fargo (WFC -0.56%), Citigroup (C -0.32%), and Bank of America (BAC -0.13%) are all huge, all profitable, and yet, all strikingly different. And its in these differences we as investors can find value and opportunity (and also avoid undue risk). 

In the slideshow below, we'll break down the fundamentals of profitability at these three megabanks to discover exactly what separates the men from the boys.