Depositories often attempt to estimate the path of future interest rates to protect their balance sheets from adverse rate movements or to capitalize on perceived market opportunities.
However, it is nearly impossible to consistently and accurately project the future path of interest rates, making balance sheet decisions based on interest rate forecasts little more than a bet on rates. Depositories looking to maintain tolerable risk levels and achieve adequate compensation for any given risk exposure must rely upon a disciplined risk evaluation and management framework to generate sustainable financial performance.
As financial intermediaries, it’s imperative to assess interest rate risk appropriately because it is one of the most critical variables driving risk to both earnings and capital. Varying repricing profiles across the asset and liability side of the balance sheet can create risk exposure to falling and/or rising rate environments, which can be captured through robust interest rate risk modeling.
As seen in recent bank failures, drastic repricing mismatches in depository balance sheets can create stress to both the balance sheet and income statement and, ultimately, impact likelihood of survival. While financial modeling is central to managing any financial institution, inadequate model sophistication and poor assumptions can significantly underestimate risk. Although financial models can’t completely insulate a depository from risk, sound modeling can greatly reduce the potential for catastrophic failure.
Matching Models to Balance Sheet Complexity
The first step in protecting the institution is to select an appropriate risk model. Management should strive for model complexity that is equal to the institution’s balance sheet complexity and congruent with intended model use. For those with a significant residential mortgage portfolio, it’s especially important to consider adopting a stochastic model to calculate optionality. Residential mortgage borrowers possess a valuable call option on rates, which isn’t as prevalent in other loan products and can vary drastically as the rate environment changes. Capturing this optionality is a critical component in measurement of interest rate risk exposure, and the design of risk-mitigating strategies such as hedging with derivatives.
Beyond offering the ability to perform intricate calculations to ensure more precise analytics, an advanced model can provide depositories with significant resources to aid in holistic asset-liability management and strategic planning. In addition to interest rate risk, they face credit and liquidity risk, as well as a multitude of esoteric factors. An advanced model can incorporate credit losses for the life of a loan to estimate the credit risk inherent in a portfolio or simulate complex growth and stress scenarios to measure periodic cash flows and capital adequacy.
Enhancing Your Interest Rate Risk Reporting
The most common methods to measure interest rate risk are the Net Interest Income (NII) and the Economic Value (NEV/EVE) simulations. Each has its strengths and weaknesses, but the combination of the two can provide a comprehensive perspective on both the short-term and long-term risk exposure driven by repricing and behavioral differences in an institution’s assets and liabilities.
Expansion beyond the high-level results for earnings and capital at risk that these simulations produce can help institutions further refine their understanding of interest rate risk exposure to the portfolio and at the instrument level. One metric that should be considered is effective duration. Effective duration is the price sensitivity of a financial instrument (i.e., investment, loan, deposit, etc.), given a change in underlying interest rates. Understanding effective duration profiles across the balance sheet can assist with strategic positioning discussions, identifying appropriate matched funding sources, and pinpointing risk anomalies that may need further oversight.
While commonly referenced by financial managers and portfolio managers alike, this metric has some flaws. The calculation itself is precise when the observed rate changes have only small variances. As market rates become more volatile, duration analytics lose precision. Another shortcoming of effective duration is the assumption that market rates move in parallel fashion, which can be a significant shortcoming when trying to develop a hedging strategy. Since rates rarely, if ever, move in a parallel fashion and long-term assets can be sensitive to multiple points along a yield curve, key rate duration analytics are more appropriate to understand the true nature of a portfolio’s sensitivity.
Key rate duration can expand upon the insights of effective duration by isolating risk exposure at each point along the yield curve. Models calculate this sensitivity by moving individual points on the curve up and down to capture valuation change associated with the micro-movement in rates. This results in a significant amount of processing time, emphasizing the need for a sophisticated model. With the resulting key rate durations, credit unions and banks can more efficiently manage unwanted risk through targeted hedging strategies.
A Key Element to Effective Asset Liability Management (ALM)
Many factors can affect a depository’s financial performance, and interest rate risk is only a single factor. However, it’s one that is core to financial intermediaries and shouldn’t be overlooked. Understanding and trusting the accuracy of risk reporting cannot occur unless a well-rounded ALM process is developed with a model that matches the institution’s balance sheet complexity. In addition to required NII and Economic Value metrics, depositories can leverage more detailed metrics, such as effective duration, to identify drivers of risk, enhance strategy discussions, and mitigate undesirable risk exposure.
If you haven’t reviewed your model assumptions or capabilities following significant change in balance sheet composition or interest rate environment, it’s likely time to evaluate whether your model is sufficient to guide effective asset liability management and balance sheet strategy.
Contact us at info@almfirst.com to discuss more best practices in interest rate risk management.
