ARMOUR Residential REIT, Inc. invests in residential mortgage-backed securities (MBS) in the United States. The company's securities portfolio primarily consists of the United States Government-sponsored entity's (GSE) and the Government National Mortgage Administration's issued or guaranteed securities backed by fixed rate, hybrid adjustable rate, and adjustable-rate home loans, as well as unsecured notes and bonds issued by the GSE and the United States treasuries, as well as money market instruments. It also invests in other securities backed by residential mortgages for which the payment of principal and interest is not guaranteed by a GSE or government agency.