Abstract: A mortgage-backed securities (MBS) processing system including a processor, a database and a computer-readable memory. The database is configured to store data pertaining to multiple mortgage-backed securities, each mortgage-backed security associated with at least one loan. The computer-readable memory includes computer-readable instructions. When the computer-readable instructions are executed on the processor to associate the multiple mortgage-backed securities stored in the database with a set of different MBS indices based on MBS indexing rules. The MBS indexing rules map a given mortgage-backed security to a given MBS index based at least in part on the credit enhancement type associated with the given mortgage-backed security.