Assume a pool of fixed-rate mortgages are packaged together into mortgage-backed securities and the cash flows of the mortgage-backed securities are split into interest only (10) and principal only (PO) strips. The IO receives all interest payments and the PO receives all principal payments What happens to the value of IOs when rate rise? Explain why. What happens to the value of POs when rates rise? Explain why What happens to the value of IOs when rate fall? Explain why. hat happens to the value of POs when rates fall? Explain why