While most commercial banks can make money primarily by lending, GS is forced to earn its profits by being smarter than other market execution platforms and thereby attracting institutional client trading volumes. (theinstitutionalriskanalyst.com)
Most commercial banks impose a more favorable step - down prepayment penalty during the fixed rate terms (ashworthpartners.com)
The World Bank has a research arm that most commercial banks do not have. (grist.org)