Where This Lesson Fits
The previous lesson introduced duration mismatch and repricing gaps as the primary ways asset–liability managers evaluate interest rate exposure across a bank’s balance sheet.
To understand those exposures fully, students must also understand how different banking products respond to interest rate changes.
Loans, deposits, and investment securities behave differently when rates rise or fall. These behavioral differences create the structural sensitivity that asset–liability management must monitor.
Lesson Objective
By the end of this lesson, students should be able to explain how loans, deposits, and investment securities react differently to interest rate changes and why those differences affect a bank’s balance sheet exposure.
Lesson Overview
Banks hold a wide range of financial instruments, each with its own maturity structure, pricing behavior, and sensitivity to market interest rates.
Some products adjust quickly when rates change, while others remain fixed for long periods. Some respond fully to market rates, while others adjust only partially because of customer behavior or competitive dynamics.
Because of these differences, interest rate changes rarely affect the entire balance sheet evenly.
Interest Rate Behavior of Loans
Loans are one of the largest categories of bank assets. Their interest rate sensitivity depends largely on whether they carry fixed or variable interest rates.
Fixed-rate loans maintain the same interest rate throughout their contractual term. When market rates rise, these loans continue generating the original interest income until maturity.
Variable-rate loans, on the other hand, periodically reset their interest rate based on a benchmark such as a prime rate or interbank reference rate.
Because of these differences, the mix of fixed and adjustable-rate loans strongly influences how asset income responds to changing rates.
Interest Rate Behavior of Deposits
Deposits are the primary funding source for most banks. However, deposit pricing does not always move in direct proportion to market interest rates.
Some deposit categories, such as demand deposits or checking accounts, often pay little or no interest and may not respond immediately to rate changes.
Other deposits, such as savings accounts or certificates of deposit, may adjust their interest rates more closely with market conditions.
Customer behavior also plays an important role. Depositors may move funds when higher yields become available elsewhere, which can change the cost and stability of funding.
Investment Securities and Market Sensitivity
Banks often hold investment securities such as government bonds, mortgage-backed securities, or other interest-bearing instruments.
Unlike loans, which may be held to maturity with contractual cash flows, securities are often valued based on current market conditions.
When interest rates rise, the market value of existing fixed-rate securities generally declines. When interest rates fall, those securities typically increase in value.
This means that investment portfolios can introduce valuation sensitivity in addition to income sensitivity.
Combining These Behaviors
The balance sheet of a bank combines loans, deposits, and investments into a single financial structure.
Because each category responds differently to interest rate movements, the overall effect of a rate change depends on how these components interact.
For example, if loan yields remain fixed while deposit costs rise quickly, net interest income may decline.
If investment securities lose market value while funding costs also increase, the bank may face both income pressure and valuation changes.
Behavioral Uncertainty
One challenge in asset–liability management is that not all financial behavior is strictly contractual.
Depositors may withdraw funds earlier than expected, borrowers may refinance loans when rates fall, and investment cash flows may change based on prepayment patterns.
Because of these behavioral uncertainties, asset–liability managers rely on models and historical patterns to estimate how customers may respond to rate changes.
Why Product Behavior Matters
Understanding how loans, deposits, and investments behave under different interest rate environments allows banks to anticipate potential earnings changes.
This information helps management decide how to structure the balance sheet, price products, and maintain financial stability under changing market conditions.
Without understanding product behavior, asset–liability management would have little ability to predict how the bank might perform when interest rates shift.
What Good Basic Interpretation Looks Like
Students should understand that interest rate risk in banking arises not simply from the existence of loans and deposits but from the way these instruments respond differently to rate changes.
Asset–liability management evaluates these differences so the institution can manage earnings stability and balance sheet resilience.
Common Misunderstandings
Thinking all banking products respond equally to rates
In reality, each product category has different repricing structures and behavioral patterns.
Assuming deposit costs always follow market rates exactly
Deposits often adjust more slowly or partially because of customer behavior and competitive pricing strategies.
Believing only loans create interest rate risk
Deposits and investment securities also contribute significantly to rate sensitivity.
Practical Exercises
Exercise 1
Explain how a bank with mostly fixed-rate loans might be affected if deposit interest rates rise quickly.
Exercise 2
Describe how investment securities can introduce valuation sensitivity when interest rates change.
Exercise 3
Discuss why customer behavior affects deposit pricing and funding stability.
Key Terms
Fixed-Rate Loan — A loan whose interest rate remains constant throughout the contractual term.
Variable-Rate Loan — A loan whose interest rate periodically resets based on market benchmarks.
Deposit Pricing — The interest rate paid to deposit customers for holding funds at the bank.
Investment Securities — Financial instruments held by banks that generate interest income and may fluctuate in market value.
Interest Rate Risk — The possibility that changes in interest rates will affect earnings or asset values.
Knowledge Check
Question 1
Why do fixed-rate loans create interest rate sensitivity?
A. Because their interest rate changes daily
B. Because their rate remains constant even when market rates change
C. Because they never generate income
D. Because they eliminate interest rate risk
Question 2
Why might deposit costs rise when interest rates increase?
A. Because depositors seek higher returns and banks adjust rates to remain competitive
B. Because deposits stop functioning
C. Because banks eliminate deposits entirely
D. Because interest rates do not affect deposits
Question 3
How do rising interest rates typically affect fixed-rate securities?
A. Their market value increases
B. Their market value decreases
C. Their value disappears entirely
D. Their value never changes
Lesson Summary
- Loans, deposits, and investment securities respond differently to interest rate changes.
- Fixed-rate loans adjust slowly, while variable-rate loans reprice periodically.
- Deposit pricing often adjusts based on customer behavior and competitive conditions.
- Investment securities may experience market value changes when rates move.
- These differences create structural interest rate exposure across the bank’s balance sheet.
Next Lesson Preview
The next lesson explores funding sensitivity and deposit repricing behavior, examining how customer behavior and funding mix influence liability-side interest rate exposure.
Continue to Lesson 36.4