The MS Mortgage Securities Trust - Class IS (MORGX) is a mutual fund that primarily invests in mortgage-backed securities. These securities are debt instruments that are backed by a pool of mortgages, providing investors with a steady stream of income through interest payments. This fund is classified as Class IS, which typically indicates a higher minimum investment requirement and lower fees compared to other classes of the same fund. MORGX may be suitable for investors seeking a diversified portfolio with a focus on fixed income investments.