Interest Rate Risk in Banking Book: CAIIB Guide

Interest rate risk in banking book (IRRBB) is one of the most heavily weighted areas in the CAIIB Bank Financial Management paper, and in 2026 it remains a favourite of examiners because it links interest-rate movements directly to a bank's earnings and economic value. This explainer breaks down how Indian banks measure, monitor and manage IRRBB under the RBI framework, so that as a CAIIB candidate you can answer both the conceptual and numerical questions with confidence. Master this and you will find adjacent topics like asset-liability management, duration and hedging far easier to crack.

What is interest rate risk in the banking book?

The interest rate risk in banking book refers to the current or prospective risk to a bank's capital and earnings arising from adverse movements in interest rates that affect its banking-book positions. Unlike the trading book, where positions are marked to market daily, the banking book holds loans, deposits and investments intended to be held over longer horizons. When rates move, the mismatch between rate-sensitive assets and liabilities can erode net interest income and the economic value of equity.

The RBI requires banks to view IRRBB through two complementary lenses:

• Earnings perspective — the impact of rate changes on near-term Net Interest Income (NII), typically measured over a one-year horizon.
• Economic value perspective — the impact on the present value of all future cash flows, captured through Economic Value of Equity (EVE).

For CAIIB purposes you should remember the three classic sub-types: repricing risk (timing mismatches when assets and liabilities reprice), basis risk (imperfect correlation between reference rates) and yield-curve risk (non-parallel shifts in the curve). You can drill these definitions further through our structured material on the CAIIB course and reinforce them with the match-the-pairs game.

The ALCO governance structure that owns IRRBB

IRRBB is not a back-office calculation; it is a board-level responsibility. The Asset Liability Committee (ALCO), chaired by the CEO or a senior executive, is the nerve centre. It sets the balance-sheet strategy, approves tolerance limits and reviews the gap and duration reports each month. The board's Risk Management Committee delegates day-to-day execution to ALCO, which is in turn supported by an ALM support group (the "middle office") that crunches the numbers.

Key responsibilities of ALCO

• Approving the interest-rate view and the funding/pricing strategy that flows from it.
• Setting prudential limits on the duration gap, repricing gaps and tolerance for EVE decline.
• Reviewing deviations and directing corrective action such as hedging or re-pricing.

A clear, well-documented governance chain matters for exams because questions often ask "who approves what". The accountability flows from the Board, to the Risk Management Committee, to ALCO, and finally to the ALM desk. Keep this hierarchy crisp in your revision notes, and test yourself with mock papers on the tests section to lock it in before the exam.

Measuring IRRBB: gap analysis and duration

Indian banks use two principal measurement tools, and CAIIB candidates must be comfortable with both. The first is the traditional gap analysis, which slots rate-sensitive assets (RSA) and rate-sensitive liabilities (RSL) into time buckets based on when they next reprice. The second is the duration gap analysis, which captures the price sensitivity of the entire balance sheet to a unit change in rates.

The repricing gap

For each time bucket, the gap is simply RSA minus RSL. A positive gap means more assets reprice than liabilities, so the bank gains when rates rise. A negative gap means liabilities reprice faster, hurting NII when rates climb. The cumulative gap across buckets, expressed as a percentage of assets, is a headline ALCO metric.

The duration gap

Duration gap = Duration of assets − (Duration of liabilities × Liabilities/Assets). A positive duration gap means the economic value of equity falls when rates rise. This single number elegantly summarises balance-sheet rate sensitivity and is central to the EVE perspective. Practise the arithmetic until it is automatic, then sanity-check current rate trends on our RBI rates resource.

RSA, RSL and the repricing buckets explained

The figure below shows how rate-sensitive assets and liabilities distribute across repricing time buckets and how the resulting duration gap emerges. Reading such a profile is a core skill: the wider the mismatch in any bucket, the more exposed the bank is to repricing risk in that horizon.

• Rate-sensitive assets (RSA) — floating-rate loans, short-tenor investments and assets maturing within the bucket.
• Rate-sensitive liabilities (RSL) — short-term deposits, borrowings and liabilities repricing within the bucket.
• Non-sensitive items — equity, fixed assets and current accounts often modelled with behavioural assumptions.

Behavioural modelling is critical for items without a contractual repricing date, such as savings and current account (CASA) balances. Banks estimate the "core" and "volatile" portions and slot them accordingly. Get this wrong and the entire gap profile distorts. For staying current with regulatory tweaks to these norms, follow the IIBF news feed and revisit explainers on our blog.

Managing and hedging interest rate risk

Once measured, IRRBB must be brought within ALCO-approved limits. Banks have an on-balance-sheet and an off-balance-sheet toolkit. On-balance-sheet, they can re-price products, alter the deposit mix, or change the tenor of new lending to close the gap. Off-balance-sheet, they deploy derivatives to hedge residual exposure.

Common hedging instruments

• Interest rate swaps — converting fixed-rate exposure to floating, or vice versa, to align repricing.
• Forward rate agreements (FRAs) — locking in a rate for a future period.
• Interest rate futures and options — managing directional and convexity risk.

The key exam idea is that hedging reduces, but rarely eliminates, risk, and it introduces basis risk of its own. Effective management also depends on robust stress testing: banks apply standardised interest-rate shocks (for example, a 200 basis-point parallel shift) to gauge the impact on EVE and NII. Confirm the live shock parameters from official sources rather than memorising figures that change. Apply this knowledge in scenario-based questions available throughout the practice tests.

For authoritative guidance, refer to the official resources of the Reserve Bank of India and the Indian Institute of Banking & Finance.

Frequently Asked Questions

In short, interest rate risk in banking book management is now a board-level discipline, and every CAIIB candidate should be able to explain how interest rate risk in banking book exposure is measured through both the EVE and NII lenses before the exam.

Conclusion: Turn IRRBB theory into exam marks

Understanding interest rate risk in banking book equips you to handle a large, high-value slice of the CAIIB Bank Financial Management syllabus in 2026. Lock in the governance chain, the gap and duration tools, and the hedging instruments, then test your recall under timed conditions. Start your structured preparation with the CAIIB course and validate your readiness with full-length mocks on the practice tests. Consistent, concept-led revision is what converts this difficult topic into reliable marks.