AG Mortgage Investment Trust, Inc. is a hybrid mortgage REIT that opportunistically invests in, acquires and manages a diversified risk-adjusted portfolio of Agency RMBS, Credit Investments, and Single-Family Rental Properties. Our Credit Investments include our Residential Investments, Commercial Investments, and ABS Investments. AG Mortgage Investment Trust, Inc. is externally managed and advised by AG REIT Management, LLC, a subsidiary of Angelo, Gordon & Co., L.P., an SEC-registered investment adviser that specializes in alternative investment activities.
The majority of our portfolio is comprised of mortgage-backed securities, specifically residential mortgage-backed securities, or RMBS. Certain of our RMBS portfolio have an explicit guarantee of principal and interest by a U.S. government agency such as the Government National Mortgage Association, or Ginnie Mae, or a federally-chartered corporation such as the Federal National Mortgage Association, or Fannie Mae, or the Federal Home Loan Mortgage Corporation, or Freddie Mac. We refer to these securities as Agency RMBS. Our Agency RMBS investments include mortgage pass-through securities and CMOs, and certain Agency RMBS whose underlying collateral is not identified until shortly (generally two days) before the purchase or sale settlement date, which we refer to as TBAs. Our portfolio also includes a significant portion of RMBS that are not issued or guaranteed by a U.S. government agency or a U.S. government-sponsored entity, or Non-Agency RMBS. Our Non-Agency RMBS investments may include fixed-and floating-rate securities, including investment grade and non-investment grade. We have invested in other target assets, including asset backed securities, or ABS, and commercial mortgage-backed securities, or CMBS, which, together with Agency RMBS and Non-Agency RMBS, we collectively refer to as real estate securities. We have also invested in commercial and residential mortgage loans, including non-performing and re-performing residential mortgage loans, as well as excess mortgage servicing rights. We have the discretion to invest in other target assets, including real estate structured finance products, other real estate-related loans and securities and direct or indirect interests in real estate.
We are externally managed and advised by AG REIT Management, LLC, a subsidiary of Angelo, Gordon & Co., L.P., or Angelo, Gordon, an SEC-registered investment adviser with approximately $32 billion under management as of December 31, 2018. Angelo, Gordon was founded in 1988 and is a privately held firm specializing in global alternative (non-traditional) investments with an absolute return orientation. The firm manages capital across four investment categories: (i) corporate credit, (ii) direct lending, (iii) securitized products, and (iv) real estate. In each discipline, the firm seeks to generate absolute returns, in all market environments and with less volatility than the overall markets, by exploiting market inefficiencies and capitalizing on situations that are not in the mainstream of investment opportunities. We believe the Angelo, Gordon platform, with extensive experience in RMBS, combined with extensive experience in CMBS, ABS, commercial real estate, net lease real estate, distressed credit, leveraged loans and private equity, enable us to selectively acquire assets to construct a diversified investment portfolio of target assets designed to produce attractive risk-adjusted returns through a combination of dividends and capital appreciation across a variety of market conditions and economic cycles.