Glossary · Rates & Instruments
Mortgage-backed Securities
Certificates represent ownership in a pool of mortgages. Holders receive regular payments of principal and interest derived from the underlying mortgage payments.
01—What is Mortgage-backed Securities?
The definition — and what it means in practice.
Mortgage-backed Securities (MBS) are certificates that represent ownership in a pool of mortgage loans. Instead of relying on one borrower, an MBS passes through cash flows from many homeowners’ monthly instalments. Investors typically receive regular payments that include both interest and repayment of principal, based on what the underlying borrowers pay. The structure and timing of payments depend on the mortgages in the pool and the security’s terms.
MBS matter because the cash flows are not as predictable as a plain bond. When borrowers repay early, your principal can come back sooner than expected; when repayments slow, cash flows can stretch out. That makes the investment sensitive to interest-rate moves and household repayment behaviour, not just “credit risk” alone. Understanding MBS helps you compare risk, income patterns, and liquidity against other fixed-income instruments.
An MBS is like owning a slice of many home loans: if the pool collects Rs 100 in instalments, investors receive their share as interest plus principal.
- An MBS represents ownership in a pool of mortgages, not a single loan.
- Payments to holders come from borrowers’ principal and interest instalments.
- Cash flows can change if borrowers repay early or repayment speeds slow.
- MBS carry interest-rate and timing (prepayment) risk, not just default risk.
- They are often discussed as fixed-income, but behave differently from plain bonds.
02—How mortgage-backed securities works on the PSX
The Pakistan-specific rules, conventions, and numbers.
On the Pakistan Stock Exchange (PSX), most retail investors encounter “mortgage-backed securities” as a concept within the wider fixed-income universe rather than as a day-to-day traded stock. If you are comparing instruments and reading about interest-rate sensitivity, yield, and different kinds of securitised assets, MBS is a common reference point for how loan pools can be turned into tradeable certificates with scheduled cash flows.
PSX trading mechanics still shape how you would access listed securities in general: the PSX is regulated by the Securities and Exchange Commission of Pakistan (SECP), trades clear through NCCPL, and holdings are maintained electronically at the Central Depository Company (CDC). Settlement is T+1 and investors need a Unique Investor Number (UIN), typically routed through a broker holding a TREC licence.
03—Common misconceptions
Where investors most often get this wrong.
An MBS pays a fixed coupon just like a normal bond.
MBS payments depend on actual mortgage repayments. Early repayments can return principal sooner and reduce future interest, while slower repayments can extend the life of the cash flows.
Diversification across many mortgages removes most risk.
Pooling can reduce single-borrower impact, but investors still face interest-rate risk, prepayment timing risk, and the possibility of broader credit stress in the mortgage pool.
MBS are the same as Sukuk because both are certificates.
“Certificate” is a broad label. Sukuk are structured to comply with Shariah principles, while conventional MBS are typically claims on interest-bearing mortgage cash flows.
04—Using mortgage-backed securities on BSL
Where this term shows up across the platform — with live data.
05—Frequently asked questions
What investors ask about mortgage-backed securities on the PSX.
Frequently Asked Questions
An MBS is a security backed by a pool of home loans. Borrowers’ monthly instalments flow into the pool, and investors receive payments made up of interest and principal, based on the security’s terms.
A bond usually has a defined maturity and coupon schedule set by the issuer. An MBS depends on how the underlying borrowers repay their mortgages, so the timing of principal repayment can change and the effective life can shorten or lengthen.
Prepayment risk is the chance that borrowers repay mortgages earlier than expected. That can return your principal sooner, reduce future interest payments, and force reinvestment at potentially different prevailing interest rates.
MBS are generally treated as fixed-income securities because they are designed to deliver periodic cash flows. However, their cash flow timing can vary, so their price behaviour can differ from plain-vanilla bonds.
Many PSX investors see MBS mainly as a concept when learning about fixed-income instruments and interest-rate sensitivity. If a security is listed, normal PSX infrastructure applies, including SECP oversight, NCCPL clearing, CDC electronic holding, and T+1 settlement.
06—Related terms
Keep building the picture.
Securities that pay a fixed return over a defined period, such as bonds or government securities. Generally considered lower risk than equities.
A fixed-income instrument representing a loan made by an investor to a borrower, typically a government or corporation. The borrower pays periodic interest and repays the principal at maturity.
The income generated by an investment over a period, expressed as a percentage of the investment's cost or current market value. Dividend yield and bond yield are the most commonly referenced forms.
The cost of borrowing money, set by the State Bank of Pakistan through the policy rate. Rising interest rates generally weigh on equity valuations by increasing the discount rate applied to future earnings.
Shariah-compliant securities representing fractional ownership in an underlying asset rather than a debt obligation. Unlike conventional bonds, which pay interest, Sukuk holders earn a share of the profit generated by the underlying asset; the Government of Pakistan issues Sukuk for both domestic and international markets.
Debt instruments issued by the Government of Pakistan to finance public expenditure. Include Treasury Bills (T-Bills) and Pakistan Investment Bonds (PIBs).
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