Mortgage-Backed Securities (MBS) Definition: Types of Investment


Mortgage-Backed Securities (MBS) are investment vehicles that have gained significant popularity in the financial markets. These securities are backed by a pool of mortgage loans, providing investors with an opportunity to earn income based on the interest and principal payments made by the underlying borrowers. Understanding the definition and types of MBS is crucial for investors looking to diversify their portfolios and explore alternative investment options.

Mortgage-Backed Securities (MBS) are financial instruments that represent an ownership interest in a pool of mortgage loans. This article provides an overview of MBS, exploring their definition and various types of investment. It highlights the benefits and drawbacks of investing in MBS and offers key insights for potential investors.

What are Mortgage-Backed Securities?

Mortgage-Backed Securities (MBS) are created when financial institutions bundle together a large number of mortgage loans into a single investment product. These loans can include residential mortgages, such as those used for purchasing homes or refinancing existing mortgages. The MBS are then sold to investors, who essentially become the owners of a portion of the underlying mortgage loans.
Investors in MBS receive periodic payments, primarily in the form of interest and principal repayments made by the homeowners. These payments are distributed among the investors based on their proportionate ownership of the MBS. By investing in MBS, individuals can indirectly participate in the housing market and earn income from the mortgage payments made by homeowners.

Types of Mortgage-Backed Securities

Pass-Through Securities

Pass-Through Securities are the most common type of MBS. They provide investors with a pro-rata share of the cash flows generated by the underlying mortgage loans. The principal and interest payments made by the homeowners are passed through to the investors, who receive regular payments based on the pool of mortgages.

Collateralized Mortgage Obligations (CMOs)

Collateralized Mortgage Obligations (CMOs) are a type of MBS that offer different risk and return profiles through tranches. Tranches represent different segments of the mortgage pool, each with its own characteristics. CMOs allow investors to choose tranches that align with their risk tolerance and investment objectives.

Mortgage-Backed Bonds

Mortgage-Backed Bonds are securities backed by a pool of mortgage loans. They typically offer fixed interest rates and maturities ranging from several years to several decades. These bonds provide investors with predictable cash flows over the life of the investment.

Pros and Cons of Investing in Mortgage-Backed Securities


Here is a list of the benefits and drawbacks to consider.


  • Potential for attractive yields
  • Diversification benefits
  • Stable cash flows
  • Backed by the underlying mortgage loans
  • Lower default risk compared to individual mortgages
  • Liquidity in the secondary market


  • Interest rate and prepayment risk
  • Exposure to economic and housing market conditions
  • Complexity in understanding the underlying mortgage pool
  • Potential for credit risk if the underlying borrowers default

Key takeaways

  • Mortgage-Backed Securities (MBS) are investment vehicles backed by pools of mortgage loans.
  • Types of MBS include Pass-Through Securities, Collateralized Mortgage Obligations (CMOs), and Mortgage-Backed Bonds.
  • Investing in MBS offers the potential for attractive yields, diversification benefits, and stable cash flows.
  • However, it comes with risks such as interest rate and prepayment risk, exposure to economic and housing market conditions, and complexity in understanding the underlying mortgage pool.
  • High-quality sources for further information on MBS include the Federal Reserve and reputable educational institutions.
View Article Sources
  1. Mortgage-Backed Securities and Collateralized –
  2. Asset-Backed Securities – Dodd-Frank Act Rulemaking –
  3. What Is a Conforming Loan? – SuperMoney
  4. Cross Collateralization: What Is It and How Does It Work? – SuperMoney
  5. What is a GSE Mortgage? – SuperMoney
  6. What is the Secondary Mortgage Market, and How Does It Work? – SuperMoney