Collateralized Mortgage Obligation

Collateralized Mortgage Obligation (CMO)

What Is a Collateralized Mortgage Obligation?

A collateralized mortgage obligation (CMO) refers to a type of mortgage-backed securities that contains a pool of mortgages and sells them as an investment. Organized by maturity and risk level, CMOs receive cash flows when borrowers repay mortgages as collateral for these securities. In turn, CMOs allocate principal and interest payments to their investors based on predetermined rules and agreements.

First issued by Salomon Brothers and First Boston in 1983, CMOs were complex and included many different mortgages. For many reasons, investors were more inclined to focus on the income streams offered by CMOs rather than the health of the mortgages themselves. As a result, many investors have purchased CMOs full of subprime mortgages, adjustable-rate mortgages, mortgages owned by borrowers whose income wasn’t verified during the application process, and other risky mortgages with a high risk of default.

The use of ECLs has been criticized as a provoking factor of the 2007–2008 financial crisis. Rising home prices made mortgages look like a safe investment, encouraging investors to buy CMOs and other MBSs. Still, market and economic conditions led to increased foreclosures and payment risks that financial models could not accurately predict. The effects of the global financial crisis have led to increased regulation of mortgage-backed securities. In December 2016, the SEC and FINRA introduced new rules that reduce the risk of these securities by setting margin requirements for covered agency transactions, including collateralized mortgage obligations.

Understanding Collateralized Mortgage Obligations

Secured mortgage obligations consist of several tranches or groups of mortgages organized by their risk profiles. Tranches typically have varying principal balances, interest rates, maturities, and default rates and represent complex financial instruments. Secured mortgage obligations are sensitive to changes in interest rates and changes in economic conditions such as foreclosure rates, refinancing rates, and the rates at which real estate is sold. Each tranche has a different maturity date and size, and bonds are issued against it with a monthly coupon. The coupon provides monthly payments of principal and interest.

To illustrate, let’s look at the mechanism in the picture. Let’s suppose that a bank issued a mortgage loan for apartments in the amount of $100,000,000 and immediately after that issued CMOs for the same amount. The pool of bonds is put up for auction. Investors receive a long-term guaranteed income with potentially low risk by purchasing bonds. The bank uses the money received from investors to issue new loans. Part of the interest on the mortgage goes to the payment of coupon income, and the rest is the bank's profit.

1080_1080px_Collateralized Mortgage Obligations_20-03-2022_EN.png


Like CMOs, collateralized debt obligations (CDOs) consist of a group of loans pooled together and sold as an investment vehicle. However, while CMOs only contain mortgages, CDOs have a range of loans such as auto loans, credit cards, commercial loans, and mortgages as well. Both CDOs and CMOs peaked in 2007, just before the global financial crisis, and their value plummeted after that. For example, at its peak in 2007, the CDO market was worth $1.3 trillion. For reference, in 2013 it already cost $850 million.


Mortgage-Backed Securities, or MBS, is any investment instrument containing a package of residential mortgages. Organizations that offer mortgage-backed securities buy these loans from banks or financial institutions.

When borrowers pay off their mortgages, MBS receives cash. Investors in MBS receive payments according to a certain schedule. The investors’ income is based on a percentage agreed between the investor and the MBS offering entity on interest and principal payments made on loans within the MBS.

CMO is a type of MBS. What makes CMOs different from traditional MBSs is that mortgages in CMOs are divided into categories or tranches based on risk and maturities.

The importance of risk level with CMO

When it comes to collateralized mortgage obligations, determining the risk level is critical.

Because CMOs are often grouped into tranches by risk, it is crucial to pay attention to them. Since CMOs are mortgage-linked, there are several reasons why some tranches are considered low-risk, such as the borrowers' credit rating or the amount of monthly debt they have.

Conversely, higher risk tranches will contain borrowers with higher credit, higher foreclosure rates and interest rates. The lower the risk, the more likely your money will be returned in total, although your payouts are likely to be lower. Again, it's all about what the investor is specifically looking for in an investment vehicle. Maybe an investor is willing to take risk if it means they can earn more in the short term.


2022-03-25 • Updated

Frequently asked questions

  • How to start trading?

    If you are 18+ years old, you can join FBS and begin your FX journey. To trade, you need a brokerage account and sufficient knowledge on how assets behave in the financial markets. Start with studying the basics with our free educational materials and creating an FBS account. You may want to test the environment with virtual money with a Demo account. Once you are ready, enter the real market and trade to succeed.

  • How to open an FBS account?

    Click the 'Open account' button on our website and proceed to the Trader Area. Before you can start trading, pass a profile verification. Confirm your email and phone number, get your ID verified. This procedure guarantees the safety of your funds and identity. Once you are done with all the checks, go to the preferred trading platform, and start trading.

  • How to withdraw the money you earned with FBS?

    The procedure is very straightforward. Go to the Withdrawal page on the website or the Finances section of the FBS Trader Area and access Withdrawal. You can get the earned money via the same payment system that you used for depositing. In case you funded the account via various methods, withdraw your profit via the same methods in the ratio according to the deposited sums.

Deposit with your local payment systems

Data collection notice

FBS maintains a record of your data to run this website. By pressing the “Accept” button, you agree to our Privacy policy.


A manager will call you shortly.

Change number

Your request is accepted.

A manager will call you shortly.

Next callback request for this phone number
will be available in

If you have an urgent issue please contact us via
Live chat

Internal error. Please try again later

Don’t waste your time – keep track of how NFP affects the US dollar and profit!

You are using an older version of your browser.

Update it to the latest version or try another one for a safer, more comfortable and productive trading experience.

Safari Chrome Firefox Opera