Commonwealth Bank of Australia

The Business

CBA holds roughly 26% of Australian household deposits and originates about one in four home loans. Its funding structure relies 79% on deposits rather than wholesale markets, giving it a structural cost advantage over smaller competitors. Four banks control 75% of the Australian banking system, protected by prudential regulation that makes new entry extremely difficult. CBA's digital platform, the most downloaded banking app in the country, reinforces deposit stickiness and reduces servicing costs. Fee income from institutional banking, wealth management, and New Zealand operations provides diversification, though net interest income (the spread between lending and deposit rates) generates roughly 84% of total revenue.

Recent Performance

CBA shares have roughly doubled from their 2020 lows, driven by a combination of post-COVID credit growth, higher interest rates lifting margins, and a re-rating of the quality premium the market assigns to the franchise. The first half of FY26 delivered $5.4 billion in cash profit, up 2% on the prior period, with a net interest margin of 2.04%. Loan impairment charges remained benign at 6 basis points of gross loans. The stock now trades at 25 times forward earnings, an 80% premium to its Big Four peers.

Outlook

We forecast total operating income growing at roughly 3% annually through FY28, as 4-5% loan book expansion offsets gradual NIM compression from deposit competition. Net profit reaches $11.0 billion by FY28, up from $10.2 billion in FY25, with earnings per share growing from $6.13 to $6.59. The key drag is provision normalisation: CBA currently books just 6 basis points in loan losses against a through-cycle average closer to 10-12 basis points, and the RBA cash rate at 4.35% has yet to fully flow through to mortgage arrears. Return on equity drifts from 13.5% toward 12.5% as the credit cycle matures.

Key Risks

The dominant risk is valuation compression: if the P/E ratio simply reverted to 18 times, the share price impact would be severe. Credit cycle escalation represents the second risk, with each basis point of normalised loss rate costing approximately $1.3 billion in annual provisions. A structural decline in NIM below 1.90% would permanently impair earnings power relative to current expectations.

What to Watch

The thesis-defining event is the FY26 full-year result in August 2026, which will reveal whether provision charges are normalising and whether NIM has stabilised above 2.00%. Any earnings miss at this valuation would test the market's willingness to sustain a 25-times multiple.

• May 2026 Q3 trading update — first read on post-rate-hike arrears and NIM trajectory; NIM below 1.95% or mortgage arrears above 0.80% would signal accelerating stress.
• 12-24 months RBA rate path — 150 basis points of cuts would materially affect the discount rate applied to bank earnings, though this remains a minority probability scenario.

Company Description

CBA operates across five segments. Retail Banking Services handles home loans, personal lending, deposits, and credit cards for approximately 16 million customers, contributing the largest share of group profit. Business Banking covers SME and commercial lending. Institutional Banking and Markets serves corporate clients with lending, transaction banking, and capital markets services. The bank maintains a wealth management arm (insurance and superannuation platforms) and operates ASB Bank in New Zealand. Together, retail and business banking generate roughly 85% of total operating income, making CBA overwhelmingly a domestic consumer and SME franchise. The remaining segments provide diversification but are not the reason investors own this stock.

Where the Growth Is

Volume growth in the core loan book is the primary earnings driver, expanding at 4-5% annually as population growth and housing turnover feed mortgage demand. Digital investment of $1.2 billion per half-year compounds CBA's advantage in deposit retention, which directly lowers funding costs and supports net interest income. Over the next five years, this volume growth should add $2-4 billion in incremental operating income, roughly offsetting the 3-5 basis points of annual NIM compression from deposit competition. The growth story is not exciting, but it is reliable: steady volume gains in a structurally protected market.

Competitive Position

CBA's advantages are deeply entrenched and unlikely to erode within a decade. The bank holds 26.6% of household deposits, the largest share in the system, and this deposit base provides lower-cost funding than any alternative. Four banks control 75% of the market under a regulatory framework (APRA's D-SIB designation) that imposes higher capital requirements on systemically important institutions, effectively creating a barrier that protects incumbents while discouraging new entry. CBA's digital platform extends this advantage: the most-used banking app in Australia, with 2,900 AI-driven service bots and growing GenAI deployment, creates switching costs that compound over time. Competitors would need billions and years to replicate this infrastructure. The competitive moat is wide and stable, sustained by regulation, scale, and technology rather than any single fleeting advantage.

Management & Capital Discipline

CEO Matt Comyn's eight-year tenure has delivered consistent execution. The bank completed a multi-year portfolio simplification, exiting wealth management businesses that generated regulatory headaches and diluted returns. Over $20 billion has been returned via buybacks alongside a 75-79% dividend payout ratio. CET1 capital (the bank's core equity buffer, expressed as a percentage of risk-weighted assets) has been maintained at 12.3%, some 205 basis points above the regulatory minimum. One honest observation: management's public framing of provision buffers as "comfortable" may prove optimistic given the RBA's aggressive tightening cycle. The $2.8 billion buffer above central-scenario provisions covers the base case but would fall short under a severe downturn requiring $8.5 billion.

Financial Position

CBA's balance sheet is a fortress by any reasonable measure. CET1 at 12.3% provides a 205 basis point buffer above APRA's 10.25% minimum. The liquidity coverage ratio sits at 132%, well above the 100% requirement. Loan-to-deposit funding at 79% is among the lowest of the Big Four, reducing reliance on volatile wholesale markets. The $2.8 billion provision buffer provides a cushion against credit deterioration, though it would be consumed quickly under a severe scenario with loss rates approaching 28 basis points. In a normal downturn, CBA can absorb higher losses while maintaining dividends and capital adequacy without difficulty.