CBA’s Share Price Fell 10%. It’s Still Not Cheap.

Commonwealth Bank of Australia (CBA) shed more than 10% of its value in a single session on 13 May 2026, the kind of move that makes long-time holders reach for a calculator and new buyers start circling. The crash was not random. A federal budget targeting investor property incentives landed on the same day CBA’s own quarterly update flagged flat operating income and a A$200 million provisions top-up. The combination hit a stock that was already trading at a multiple that made many professional investors uncomfortable. The question dominating Australian investing forums, analyst desks, and social feeds is the same: does the sell-off finally make CBA cheap? What follows unpacks whether the post-crash CBA share price represents fair value or a value trap, using specific valuation metrics, peer comparisons, and policy impact modelling to give investors a clearer framework for deciding whether to buy, hold, or step back.

What actually happened to CBA on 13 May, and why it matters for valuation

CBA closed at A$171.57 on 12 May. By the following session’s intraday low, shares had fallen to A$153.67. The stock settled at A$154.01, a 10.23% single-session decline that briefly stripped CBA of its position as the largest company on the ASX, handing the title to BHP.

The sell-off was not a single-catalyst event. Two forces compressed the share price simultaneously:

• Federal budget policy changes: The removal of negative gearing (effective 1 July 2027) and the halving of the capital gains tax (CGT) discount to 25% directly threaten investor mortgage demand, CBA’s largest exposure among the Big Four.
• CBA Q3 quarterly update: The ASX filing on 13 May disclosed flat operating income and a A$200 million provisions top-up, citing “policy headwinds” as a contributing factor.

JP Morgan note, 13 May: “CBA’s premium gone; trading at NAB levels now but provisions signal pain.”

Before the crash, CBA’s price-to-earnings (P/E) ratio sat materially above 25x. As of the 14 May close, CBA trades at A$153.92, with a P/E of 25.1x on FY27 estimated earnings per share (EPS) of A$6.13. A 52-week low of A$151.00 was touched on the morning of 14 May before a partial recovery to approximately A$154.50.

The scale of the 13 May sell-off is best understood against the pre-crash Big Four valuations that had already drawn unanimous sell ratings from analysts covering CBA, with all 14 brokers in coverage carrying sell ratings and an average price target of approximately A$130 as recently as late April 2026, a consensus that now looks prescient rather than contrarian.

The distinction matters for anyone considering buying the dip. The crash compressed the share price, but it did not reset the earnings base. The P/E denominator, the number that determines whether the multiple is justified, faces its own set of pressures.

Understanding price-to-earnings and price-to-book: the two lenses every CBA investor needs

A P/E ratio of 25.1x means an investor buying CBA today is paying $25.10 for every $1 of expected annual earnings. Compare that to a stock trading at 12x: the same dollar of earnings costs less than half the price. For CBA, the question is whether the bank’s earnings quality and growth profile justify that premium, or whether the market has been overpaying for perceived safety.

P/E captures the relationship between price and profits. For banks, though, a second metric often tells a sharper story.

Why price-to-book matters more for banks than for tech stocks

Technology companies hold few hard assets, so book value is a poor proxy for what the business is actually worth. Banks are different. A bank’s core business is managing a leveraged balance sheet of loans and deposits, and book value represents a reasonable approximation of what shareholders actually own.

CBA’s price-to-book (P/B) ratio sits at 3.8x, based on a book value of A$40.52 per share. That means the market is pricing CBA at nearly four times the value of its underlying assets. A high P/B is only defensible if the business generates a sustainably high return on equity (RoE), the measure of how effectively the bank turns shareholder capital into profit.

CBA’s RoE is 15.2%. JPMorgan Chase, by comparison, generates a 16.0% RoE but trades at a P/B of just 1.9x.

For investors applying this lens, the test is straightforward:

1. Find book value per share (CBA: A$40.52).
2. Divide the current share price by book value (A$153.92 ÷ A$40.52 = 3.8x).
3. Compare the resulting P/B to peer benchmarks at similar RoE levels to assess whether the premium is earned.

Investors wanting to build their own fair value range for CBA rather than relying solely on broker consensus targets will find our comprehensive walkthrough of ASX bank valuation methods covers the PE, P/B, Dividend Discount Model, and DCF frameworks in sequence, including the Australian-specific adjustments for franking credits and APRA capital requirements that make direct comparisons with international bank peers systematically misleading without them.

CBA at 25x earnings versus NAB at 18x, JPMorgan at 13x, and HSBC at 8.5x: what the peer table reveals

The domestic gap is the starting point. National Australia Bank (NAB) trades at 17.8x earnings with a 1.6x P/B and an RoE of 11.0%. CBA’s P/E sits 1.4x above NAB’s, a premium Goldman Sachs’ AU Banks team described on 14 May as “unsustainable” given that peers average a P/E of 12x on lower provisions risk.

The global comparison widens the gap further.

The paradox sits in the JPMorgan line. A bank with a higher RoE than CBA (16.0% versus 15.2%) trades at roughly half the P/B multiple. Santander generates a 12.1% RoE and trades at 0.7x book, a fraction of CBA’s 3.8x.

The P/E and P/B comparison captures the valuation gap between CBA and its peers, but NIM and CET1 capital ratios determine whether that gap reflects genuine earnings quality differences or simply accumulated market sentiment; NAB’s H1 2026 NIM of approximately 1.71% sits below the sector average of 1.78%, while CBA’s relative NIM advantage is one of the structural justifications its bulls have historically cited for the premium.

According to UBS’s “Global Banks Outlook” note on 13 May, Australian banks trade at a 40% P/B premium to US and UK peers despite similar RoE profiles. UBS suggested the budget may begin to normalise that premium toward 3x.

Morningstar data reinforces the picture: the ASX Big Four average a P/B of 2.8x versus a global bank average of 1.5x. CBA sits well above even that elevated domestic average. For additional context, CBA trades at a higher P/E than Meta Platforms (22.4x), despite being a mature, regulated bank rather than a high-growth technology platform.

The budget’s long shadow: how negative gearing removal reshapes CBA’s mortgage book

CBA’s mortgage book exceeds A$400 billion, with investor lending comprising approximately 25% of the total. That concentration is the reason the budget’s two property-focused policy changes hit CBA harder than any other Big Four bank.

How investor property lending became CBA’s biggest valuation risk

Negative gearing allows property investors to offset rental losses against other income, reducing their taxable income and making leveraged property purchases more attractive. Its removal, effective 1 July 2027, strips that incentive. Property investors who relied on the tax offset to make negative-cashflow holdings viable face a fundamentally changed equation.

PwC Australia’s federal budget tax analysis confirms that from 1 July 2027 negative gearing will be limited for established residential properties acquired after 12 May 2026, and that the 50% CGT discount will be replaced by cost base indexation for assets held beyond 12 months, materially altering the after-tax equation for leveraged property investors.

The halving of the CGT discount from 50% to 25% compounds the pressure. A lower after-tax gain on sale suppresses property turnover and, with it, new loan origination. Fewer transactions mean fewer mortgages written.

Macquarie’s van der Merwe told the AFR on 14 May: “Investor retreat hits CBA hardest, 32% exposure vs. NAB’s 22%.”

The earnings impact is where the valuation case becomes uncomfortable.

UBS and Macquarie modelling projects a 5-8% contraction in CBA’s mortgage book over two years. CBA’s own Q3 ASX update on 13 May acknowledged the direction of travel, flagging the A$200 million provisions top-up partly attributable to “policy headwinds.” A valuation case for CBA must now account for whether the earnings base will shrink before it grows again.

Where analysts and fund managers are drawing the line on fair value

The post-crash analyst target range maps a narrow band of disagreement, but the tone within that band is telling.

Even the bull case, Goldman Sachs at A$165, implies the stock remains materially below pre-crash levels. The bear case from UBS at A$158 sits only A$4 above the current price. Consensus at A$162.40 implies approximately 5.5% upside, a thin margin for a stock facing an unresolved policy overhang.

Institutional activity reinforces the caution:

• BlackRock Australia trimmed its 2% stake (ASX filing, 13 May).
• No broker upgrades were issued in the 48 hours following the crash.
• Five downgrades or neutral shifts were recorded against zero upgrades.

Perpetual’s Ryan told the AFR on 14 May that CBA appeared “fairly valued at 23x but risks 20% downside on budget.” Magellan’s Byrne flagged A$150 as the support level under monitoring. Retail sentiment tracked a similar line: HotCopper’s top-rated post called the 25x P/E a “joke post-budget,” with the consensus waiting for A$140. A Livewire poll showed 55% of respondents favouring sell or hold.

When professional scepticism and retail bearishness align, the conditions for a swift recovery bounce historically weaken.

At A$154, the premium has shrunk but the problem has not gone away

The crash moved the price. It did not move the earnings trajectory. At A$153.92 and FY27E EPS of A$6.13, the P/E sits at 25.1x. If the A$400-600 million profit drag from the budget’s property policies materialises, EPS could fall toward A$5.80-5.90, pushing the effective forward P/E above 26x. The P/B of 3.8x remains the highest of any major bank globally at a comparable RoE.

The consensus target of A$162.40 implies approximately 5.5% upside from current levels, a thin margin given the policy uncertainty.

For CBA at A$154 to be genuinely cheap, several conditions would need to hold:

• Earnings hold near current estimates, meaning the budget’s impact on investor lending is overstated.
• CBA’s 15.2% RoE is sustained or improves, defending the premium over global peers.
• Institutional selling reverses and capital rotates back rather than toward NAB or Westpac.

For CBA at A$154 to prove a value trap, a different set of conditions applies:

ASX 200 bank concentration risk compounds the CBA decision for investors who already hold domestic index funds or superannuation with an Australian equity tilt, since the Big Four collectively represent roughly 25% of the entire index, meaning a position in CBA alongside broad ASX exposure can push total bank allocation well above 40% of a domestic equity portfolio without the investor registering it as a concentrated sector bet.

• The A$400-600 million profit drag materialises in full, compressing EPS below A$6.00.
• The 32% investor lending concentration accelerates book contraction beyond UBS and Macquarie base cases.
• The RoE premium narrows, removing the justification for a P/B that is double JPMorgan’s.

Three data points will determine which scenario unfolds in coming months:

• H2 FY26 mortgage growth figures, the earliest direct proxy for budget impact on CBA’s loan book.
• CBA’s RoE trajectory in the FY27 results, which will confirm or undermine the premium-justified case.
• Any reversal of institutional selling, particularly BlackRock’s position, as a signal of whether large holders view the correction as sufficient.

The crash created a lower entry point. Whether it created a good one depends on numbers that have not yet been reported.

This article is for informational purposes only and should not be considered financial advice. Investors should conduct their own research and consult with financial professionals before making investment decisions. Past performance does not guarantee future results. Financial projections are subject to market conditions and various risk factors.