The Language of Sectors

Private banking is one of the most metrics-driven sectors in Indian equity markets. Banks operate with high leverage, and their core business—accepting deposits and lending money—requires careful monitoring of profitability, asset quality, and liquidity ratios. Understanding key metrics like NIM, CASA, and GNPA is essential for evaluating a bank's financial health.

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Key Takeaways

• Net Interest Margin (NIM) is the primary indicator of a bank's core lending profitability—look for stability around 3.5% to 4.5% for private banks
• CASA ratio above 40% signals a strong deposit franchise and lower funding costs
• GNPA below 2% indicates disciplined underwriting; track the trend direction quarter-over-quarter
• A Credit-Deposit ratio between 80% and 90% suggests healthy utilization without excessive risk
• Watch for divergence between operating profit and net profit growth—it may indicate provisioning manipulation

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Understanding Private Bank Metrics

Banks function fundamentally as intermediaries: they accept deposits at one interest rate and lend those funds at a higher rate. The difference—the spread—drives profitability. Unlike manufacturing companies where revenue comes from selling products, a bank's revenue depends on the cost of its "raw material" (deposits) and the yield on its "output" (loans).

This model creates unique risks. Banks are highly leveraged, often operating with equity of just 10-15% of total assets. A small percentage of loans going bad can wipe out capital. Additionally, banks must maintain sufficient liquidity to meet withdrawal demands while maximizing the deployment of funds into earning assets. These dynamics make banking metrics fundamentally different from those used in other sectors.

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Net Interest Margin (NIM)

What it is: Net Interest Margin is calculated by dividing net interest income (interest earned minus interest paid) by average interest-earning assets. It is expressed as a percentage and represents the spread a bank earns on its lending activities.

Why it matters: NIM is the primary indicator of a bank's core profitability. It reflects how effectively management prices loans relative to funding costs. A stable NIM indicates disciplined lending practices and efficient liability management.

What good looks like: Indian private sector banks typically maintain NIMs between 3.5% and 4.5%. HDFC Bank historically operated at 4.0% to 4.1% (though post-merger compression brought this to approximately 3.4%). Axis Bank and Kotak Mahindra Bank generally maintain NIMs in the 3.7% to 4.5% range.

Red flag: A sudden spike in NIM may indicate increased lending to higher-risk borrowers to boost short-term profitability. Conversely, NIM compression exceeding 20-30 basis points YoY warrants investigation into rising deposit costs or competitive pressures.

Example from earnings call:

"Our net interest margin stood at 3.99%... we anticipate that the rising cost of funds will contribute to further margin moderation." — Axis Bank Q2 FY25 Earnings Call

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CASA Ratio

What it is: The CASA ratio measures the proportion of a bank's total deposits held in Current Accounts (paying 0% interest) and Savings Accounts (typically paying 3-4% interest). Formula: (Current Account Deposits + Savings Account Deposits) / Total Deposits × 100.

Why it matters: CASA deposits represent low-cost funding. A higher CASA ratio translates directly into lower cost of funds, which supports healthier NIMs. Banks with strong CASA franchises have a structural competitive advantage.

What good looks like: A CASA ratio above 40% is considered strong for Indian private banks. Kotak Mahindra Bank and Axis Bank typically maintain ratios in the 42-43% range. HDFC Bank has historically been a leader in gathering granular, low-cost deposits.

Red flag: A CASA ratio below 35% forces the bank to rely on expensive bulk deposits and certificates of deposit to fund lending, which compresses margins and increases vulnerability during tight liquidity conditions.

Example from earnings call:

"CASA ratio of the bank improved to 42.3% at 30th September... We saw granular YoY growth in average low-cost deposits." — Kotak Mahindra Bank Q2 FY25 Earnings Call

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Credit-Deposit Ratio (CD Ratio)

What it is: The Credit-Deposit ratio measures how much of a bank's deposit base has been deployed as loans. Formula: Total Advances / Total Deposits × 100.

Why it matters: This ratio indicates how efficiently a bank utilizes its deposits while maintaining prudent buffers. Too low suggests underutilization of resources; too high indicates potential liquidity stress and reliance on non-deposit funding.

What good looks like: A CD ratio between 80% and 90% is generally considered optimal. This range allows for adequate loan growth while maintaining liquidity buffers for deposit withdrawals and regulatory requirements.

Red flag: A CD ratio exceeding 100% indicates the bank is lending more than its deposit base, funding the gap through borrowings or bonds. HDFC Bank's post-merger ratio exceeded 137%, prompting management to prioritize deposit mobilization over loan growth until the ratio normalized to approximately 94%.

Example from earnings call:

"Credit to Deposit ratio reduced from 137.0% at merger to 93.9%... Incremental credit deposit ratio was low for six years." — HDFC Bank Annual Report FY24

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Gross Non-Performing Assets (GNPA)

What it is: GNPA represents the total value of loans where borrowers have failed to make payments for 90 days or more, expressed as a percentage of total advances. Formula: Gross NPAs / Gross Advances × 100.

Why it matters: GNPA indicates the quality of a bank's loan underwriting. It reveals how much of the loan book has "gone bad" before accounting for any provisioning or recoveries. The trend direction is as important as the absolute level.

What good looks like: For top-tier Indian private banks, GNPA between 1.0% and 2.5% is considered manageable. Below 1.5% is exceptional. HDFC Bank, ICICI Bank, and Kotak Mahindra Bank have maintained GNPAs in this range during normal economic conditions.

Red flag: GNPA above 5% signals poor underwriting standards. A sudden spike in a single quarter—such as a jump from 2% to 4%—may indicate previously hidden stress being recognized, often following regulatory intervention.

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Net Non-Performing Assets (NNPA)

What it is: NNPA measures the residual credit risk after deducting provisions (reserves set aside for bad loans) from gross NPAs. Formula: (Gross NPAs - Provisions) / (Gross Advances - Provisions) × 100.

Why it matters: While GNPA shows total bad loans, NNPA reveals the actual uncovered risk. A bank with high GNPA but low NNPA has adequately provisioned for expected losses. NNPA represents the potential capital erosion if borrowers default completely.

What good looks like: NNPA below 0.5% indicates the bank has essentially covered its bad loan exposure. Most well-managed private banks maintain NNPA in the 0.3% to 0.7% range.

Red flag: A stable GNPA accompanied by rising NNPA suggests the bank has reduced provisioning to boost reported profits, leaving the balance sheet exposed to future shocks.

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Slippages

What it is: Slippages refer to loans that have freshly turned non-performing during a quarter—accounts that were standard (performing) at the start of the period but crossed the 90-day overdue threshold by quarter end.

Why it matters: While GNPA is a stock measure (cumulative bad loans), slippages are a flow measure indicating the current rate of asset quality deterioration. Rising slippages signal potential future NPA increases.

What good looks like: Slippages under 2% of advances on an annualized basis are generally manageable. Sequential decline in slippages indicates improving underwriting quality or favorable economic conditions.

Red flag: A spike in retail or unsecured loan slippages is particularly concerning as these tend to be smaller, numerous accounts that are difficult to recover. Corporate slippages are "lumpy"—one large default can significantly impact the quarter.

Example from earnings call:

"The bank expects slippages to normalize... however, the bank expects the slippages to be lower in the corporate segment." — Axis Bank Q2 FY25 Earnings Call

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Credit Cost

What it is: Credit cost represents the provisions charged to the profit and loss account during a period as a percentage of average advances. It measures the "insurance premium" a bank pays against loan losses.

Why it matters: Credit cost directly impacts profitability. Consistent, moderate credit costs indicate disciplined provisioning. Volatile credit costs suggest either lumpy corporate defaults or inconsistent provisioning policies.

What good looks like: A credit cost between 0.5% and 1.0% is typical for well-managed private banks during normal economic conditions. Axis Bank targets a "normalized" credit cost of 0.5% to 0.7%.

Red flag: Credit cost below 0.2% during economic stress suggests under-provisioning. Negative credit cost (provision write-backs) should be viewed skeptically—it may indicate profit management through release of prior provisions.

Example from earnings call:

"Credit costs have come down from 93 to 79 basis points sequentially... Slippages during Q2 were also lower at ₹1,629 crores versus ₹1,812 crores." — Kotak Mahindra Bank Q2 FY25 Earnings Call

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Provision Coverage Ratio (PCR)

What it is: PCR measures what percentage of gross NPAs has been covered by provisions. Formula: Provisions held against NPAs / Gross NPAs × 100.

Why it matters: A higher PCR indicates greater preparedness for potential loan losses. It is the inverse lens of NNPA—high PCR results in low NNPA.

What good looks like: PCR above 70% is considered prudent. Top private banks often maintain PCR between 70% and 80%, with some exceeding 85% during stress periods.

Red flag: PCR declining over consecutive quarters while GNPA remains stable or increases suggests the bank is prioritizing short-term profits over balance sheet resilience.

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Liquidity Coverage Ratio (LCR)

What it is: LCR measures a bank's stock of high-quality liquid assets (HQLA) against projected net cash outflows over a 30-day stress scenario. It is a regulatory requirement under Basel III norms.

Why it matters: LCR ensures banks can survive short-term liquidity shocks without requiring emergency central bank support. It reflects prudent liquidity management.

What good looks like: The regulatory minimum is 100%. Well-managed banks typically maintain LCR between 110% and 130%, providing a buffer above requirements.

Red flag: LCR hovering just above 100% indicates the bank is optimizing for the regulatory minimum rather than maintaining genuine liquidity buffers.

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Cost-to-Income Ratio

What it is: The Cost-to-Income ratio measures operating expenses as a percentage of operating income (net interest income plus non-interest income). It indicates operational efficiency.

Why it matters: Lower ratios indicate the bank generates more revenue per rupee of operating expense. This ratio reflects branch network efficiency, technology investments, and workforce productivity.

What good looks like: Indian private banks typically operate with Cost-to-Income ratios between 40% and 50%. Ratios below 45% indicate strong operational efficiency.

Red flag: A rising Cost-to-Income ratio without corresponding revenue growth or investment in future capabilities suggests declining efficiency or cost control issues.

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Common Analysis Pitfalls

Evergreening

Evergreening occurs when a bank issues a new loan to a borrower specifically to repay an existing overdue loan. On paper, the original loan appears "repaid" and the new loan is "performing." In reality, the bank has simply deferred recognition of the bad loan.

Indicators include: loan book growth without corresponding cash collections, divergence between reported slippages and actual GNPA reduction, and a rising "restructured book" without clear economic justification.

Technical Write-Offs

Banks may "write off" bad loans to clean up reported GNPA without actually recovering the cash. This improves GNPA ratios on paper but does not reflect genuine resolution. Track the difference between operating profit growth and net profit growth—if net profit rises significantly due to lower provisions while operating profit is flat, scrutinize the provisioning policy.

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Quick Reference

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