One of the biggest reversals at the top of the bluechip index has unfolded across the ASX 200 this year, with BHP Group surging past Commonwealth Bank of Australia to take the top spot by an ever widening margin. We are going to take a look at how BHP dethroned CBA at the top of Australia’s most valuable company list, and compare the two since the turn of 2026.
To start with, let’s clear up the market cap leadership, as BHP shares have delivered a 33.8% year-to-date gain, lifting the company’s market cap to A$311.25 billion in the process. That compares to CBA’s current market cap of around A$256.9 billion, a huge swing from the start of 2026, when CBA held a 30% lead over its mining rival. BHP now holds close to a 20% lead in the other direction.
September, however, has brought some volatility to both names, alongside the broader index. BHP shares are down 7.5% during the month, pulling back to A$61.22 after retesting the A$60 handle. CBA shares have fared somewhat better in percentage terms, declining 4.73% to A$152.33, although the technical picture looks worse. CBA has been fighting to hold the psychologically significant A$150 level, with bulls under increasing pressure to defend that floor.
BHP vs CBA: What Has Been Driving The Gap?
The engine behind BHP’s re-rating is a structural shift in its earnings, as Copper overtook iron ore as the single largest contributor to BHP’s underlying EBITDA, accounting for approximately 54% of earnings, as global copper prices have surged past US$13,900 per tonne. Iron ore has meanwhile held at a constructive US$105 to US$110 per tonne range, providing a stable secondary earnings pillar.
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BHP’s full-year update reinforced the bullish narrative, with the company distributing US$8.7 billion in dividends and outlining a self-funded plan to grow copper production by 50% by the mid-2030s. Markets have responded by re-rating BHP from a traditional cyclical iron ore miner to a credible energy-transition play, commanding a P/E of 22.52 times earnings and a dividend yield of approximately 3.9%.
CBA’s story has gone the other way, with the bank delivering a record FY26 cash profit of A$10.98 billion, supported by a return on equity of 14% and a CET1 capital ratio of 12%, metrics that in isolation speak to genuine operational resilience. However, the May trading update proved to be a significant inflection point, triggering a single-day decline of 10% after management flagged rising bad and doubtful debts and announced a A$200 million provision top-up.
Mortgage arrears have climbed to 0.73% and personal loan arrears to 1.72%, against a backdrop of forecasts from major Australian banks predicting house price declines of 8% to 10% in Sydney and Melbourne. CBA carries a provision buffer of A$2.7 billion, but with the stock still trading at 23.37 times earnings, the margin for error is thin. Analyst consensus targets sit near A$125, implying potential downside of up to 20% from current levels.
Valuation Gap Closing
The valuation gap between the two stocks remains modest on a headline P/E basis, with BHP at 22.52 times versus CBA’s 23.37 times, but the divergence in earnings trajectories and macro tailwinds makes the comparison more mixed than the numbers alone suggest. BHP also offers a marginally superior dividend yield of approximately 3.9% against CBA’s 3.3%, adding to its relative appeal for income-focused investors.
As BHP’s market cap lead over CBA widens, index-tracking funds are mechanically compelled to increase their BHP weighting and trim CBA exposure during rebalancing cycles. The self-reinforcing nature of this rebalancing adds a technical layer to what is already a compelling fundamental story for the miner.
Technical Setup
On the technical front, the two stocks once again look very different.
BHP, despite its September pullback, remains structurally intact above its 200-day simple moving average of A$56.00. The current RSI of 45.19 reflects neutral momentum rather than exhaustion, and the A$60 handle has so far held as a meaningful support level to the rally. The more immediate challenge is reclaiming the 50-day SMA of A$62.29, which currently acts as overhead resistance.
CBA’s technicals are more concerning to bulls, with the 50-day SMA at A$165.06 having crossed below the 200-day SMA at A$165.78, confirming a death cross formation, a pattern that technical traders look to as a signal of bearish momentum. The RSI of 35.9 is approaching oversold territory, which could attract short-term bargain hunters, but the structural headwinds from the housing market, margin compression, and a demanding valuation multiple are likely to cap any meaningful recovery unless the macro backdrop shifts materially.
What Lay Ahead
Looking to the next leg for each of the two ASX giants, BHP’s path from here is tied to the durability of the copper supercycle and Beijing’s appetite for industrial stimulus, while CBA’s recovery depends on whether Australian household balance sheets can absorb the current period of stress, alongside the rate path from the RBA.
The great ASX leadership flip of 2026 captures two very different stories playing out at the top of the index, and whether BHP’s lead continues to stretch, or CBA stages a recovery will depend heavily on the macro backdrop into this final quarter.
