How to Read a Bank's Financials: NIM, CASA, NPA and Why ROCE Does Not Apply

A bank’s financial statements are read differently from those of a normal company because, for a bank, deposits and borrowings are the raw material of the business rather than merely a way to fund it. That single fact breaks the ratios most investors reach for first: return on capital employed (ROCE) and debt-to-equity stop being meaningful, and the analysis shifts instead to the margin a bank earns on money, the cheapness of its funding, the quality of its loans, and the thickness of its capital cushion.

For an ordinary manufacturer, debt is a financing choice layered on top of a business that makes and sells things. For a bank, taking in money and lending it out is the business. A bank funds itself with deposits and borrowings by design, and its assets are overwhelmingly loans and investments. This is why Altys deliberately leaves the ROCE field blank for banks. Applying a factory ratio to a lender produces a number that looks precise and means very little. Below are the metrics that do the work, illustrated with two of India’s larger private lenders, HDFC Bank and ICICI Bank, used here only as neutral examples of how the figures are structured, never as a view on either stock.

Why the usual ratios break

Start with the balance sheet. A well-run private bank in India might carry deposits and borrowings many times the size of its equity. On a manufacturer, that leverage would look alarming. On a bank it is simply the shape of the business: the deposits are the inventory. Debt-to-equity, which treats borrowings as a red flag, therefore misfires. So does ROCE, which asks what a company earns on the capital it has put to work, because for a bank almost all the “capital employed” is other people’s money held on deposit.

The metrics that survive are the ones that judge a bank on its assets and its shareholders’ funds directly.

• Return on assets (ROA) measures net profit against total assets. It answers a clean question: for every rupee of assets the bank carries, how much profit does it extract? A strong private Indian bank typically runs an ROA of around 1.5 to 2 percent. That may sound thin, but on a very large asset base it compounds into substantial profit, and small movements in ROA move the whole story.
• Return on equity (ROE) measures profit against shareholders’ funds and captures how hard the bank’s own capital is working. ROA and ROE together, read alongside how much leverage links them, are the honest profitability lens for a lender.

For a bank, deposits are not debt to be minimised. They are inventory to be gathered cheaply and lent out profitably. That inversion is why the standard corporate ratios do not travel.

Net Interest Margin: the spread that pays the bills

The core engine of a bank is the gap between what it earns on loans and what it pays on deposits. Net Interest Margin (NIM) captures this: it is net interest income (interest earned minus interest paid) expressed against interest-earning assets. In plain terms, it is the spread the bank keeps on the money it moves.

Indian private banks have historically operated NIMs in the region of 3 to 4 percent, and these figures are disclosed in quarterly results and investor presentations. Two things matter more than the level itself. First, a higher NIM points to pricing power on loans and cheap funding on deposits. Second, stability matters as much as height. A NIM that holds steady through rate cycles suggests the bank is not chasing margin by taking on riskier loans or scrambling for expensive deposits when rates rise.

NIM does not stand alone. A bank can lift its margin by lending to weaker borrowers at higher rates, which flatters NIM today and shows up as bad loans later. So margin is always read together with asset quality, never in isolation.

CASA: why cheap deposits win

If NIM is the spread, the CASA ratio explains a large part of why one bank’s spread is wider than another’s. CASA stands for current account and savings account deposits, and the ratio is their share of total deposits. These are the cheapest money a bank can hold. Current accounts typically pay no interest at all, and savings accounts pay a low regulated or administered rate, so a bank funded heavily by CASA carries a lower cost of funds than one leaning on fixed deposits, which pay more.

A high CASA ratio, therefore, tends to feed directly into a healthier and more durable NIM. Large private banks such as HDFC Bank and ICICI Bank have generally reported CASA ratios in the range of the low-to-mid 40s in percentage terms in recent years, though this moves with interest rate cycles: when fixed-deposit rates climb, savers shift money into term deposits and CASA tends to slip. Watching the direction of CASA over several quarters tells you whether a bank’s funding advantage is holding or eroding.

Ratio	What it measures	Read it as
ROA	Net profit against total assets	Core profitability; roughly 1.5 to 2 percent is strong for a private bank
ROE	Net profit against shareholders’ funds	How hard the bank’s own capital works
NIM	Interest spread against interest-earning assets	Pricing power and funding cost; stability matters
CASA ratio	Current and savings deposits as a share of total deposits	Cheapness of funding; higher is cheaper
Gross NPA	Bad loans as a share of gross advances	Headline stress in the loan book
Net NPA	Bad loans net of provisions, as a share of advances	Stress not yet covered by provisions
PCR	Provisions held against gross NPAs	Cushion already set aside for bad loans
CAR / CRAR	Capital against risk-weighted assets	Ability to absorb losses and keep lending

Asset quality: where lending goes wrong

Loans are a bank’s assets, so the quality of those loans is the quality of the business. The key measures are Gross NPA and Net NPA, where NPA stands for non-performing asset, meaning a loan that has stopped being serviced (typically no interest or principal for 90 days). Gross NPA is bad loans as a percentage of total advances. Net NPA is what remains after subtracting the provisions the bank has already set aside against those loans, and it is the more conservative view of stress still sitting uncovered on the books.

The gap between the two is bridged by the provision coverage ratio (PCR), the share of gross NPAs already provided for. A high PCR means the bank has front-loaded the pain and set money aside; a low PCR means future provisions could still eat into profit. Alongside these, analysts watch slippages, the fresh loans turning bad in a given period, because a stock of NPAs can be falling even as new problems build underneath.

In recent years the larger private banks have reported gross NPA ratios that are low by the standards of the wider Indian system, often around or below a couple of percent, with net NPA figures well under that after provisioning. Rising NPAs, faster slippages, or a falling PCR are the classic early signals of credit stress, and they usually deserve more weight than a strong quarter of margin.

Capital adequacy: the cushion that lets a bank grow

Finally, a bank must hold enough capital to absorb losses and keep lending. The Capital Adequacy Ratio (CAR), also called CRAR (Capital to Risk-weighted Assets Ratio), measures a bank’s capital against its risk-weighted assets under the Basel norms that the RBI applies. Riskier assets carry higher weights, so the ratio scales the cushion to the danger in the book.

Indian banks are required to hold CAR above a regulatory minimum (the Basel III floor plus buffers set by the RBI, which for well-run private banks lands in the low double digits as a floor), and strong private lenders typically operate comfortably above it. Capital matters for two reasons. It is the shock absorber that lets a bank survive a wave of bad loans, and it is the fuel for growth, because every new loan consumes capital. A bank running close to its minimum has less room both to withstand stress and to expand.

How it fits together

None of these numbers means much alone. Read together, they describe a coherent machine. A strong bank tends to earn a healthy and stable NIM, funded by a high CASA ratio that keeps its cost of money low; it keeps NPAs low and stable with solid provision coverage, so the margin it reports is real rather than borrowed from the future; and it sits on comfortable capital, which lets it absorb the occasional bad year and keep lending through it. When those four pillars move together in the right direction, the ROA and ROE follow. When margin looks strong but asset quality is quietly deteriorating, or when growth is running ahead of capital, the composite picture tells you more than any single line item.

What to watch for in a bank

• Ignore ROCE and debt-to-equity. They are not built for a business whose raw material is deposits. Anchor on ROA and ROE instead.
• Check whether NIM is high and stable, not just high in one strong quarter, and ask what is driving it.
• Follow the direction of CASA, since a slipping CASA ratio quietly raises funding costs and pressures margin.
• Read Gross NPA, Net NPA, PCR and slippages together. A low NPA stock with rising slippages is a warning, not a comfort.
• Confirm capital sits comfortably above the RBI minimum, because a thin cushion limits both resilience and growth.
• Watch the pillars as a set. Strong margin paired with weakening asset quality or stretched capital is the pattern worth scrutinising most.

Altys Labs is not a SEBI-registered Research Analyst or Investment Adviser. This article is educational and does not recommend buying, selling or holding any security. HDFC Bank and ICICI Bank appear only as neutral illustrations of how bank financials are structured. Figures are approximate, drawn from public filings and RBI disclosures, and change over time.