FNMA isn't a servicer, they are the 'guarantor' of MBS. Basically they take about 0.5% interest of every loan in the country in exchange for guaranteeing the end investor will be made whole up to 80% loan to value. They are the most profitable entity in the country, and basically enable a stealth tax. There is value in what they provide but they produce profits that are just crazy. Wells Fargo is still probably about the tops, but they service loans for FNMA, and aren't producing like they used to. Given their book though, they still service probably as many or more loans than anyone. Wells has been reducing its market share as of late, and has the asset cap I think. Not a big deal. Still huge.