Commonwealth Bank lost about $30bn in value on Wednesday, the largest single-day slide in its history, after quarterly results that showed a $2.7bn profit, up 4 per cent. The Cba Share Price Drop rattled the market and pushed BHP past the lender to become the most valuable company on the ASX.

The scale of the move was striking because Commonwealth Bank is not a small part of the market. It holds about 26 per cent of investor mortgages in Australia and accounts for roughly 10 per cent of the S&P/ASX 200, meaning a sharp shift in its shares can move the broader index. The company’s fall also came despite a result that, on paper, still showed earnings growth.

That contrast is what has shaken investors. Over the past year, the ASX financial sector has gained 2.25 per cent, but it has shed 8.9 per cent in the past month. By comparison, BHP’s share price has increased 57 per cent over the past year, and the ASX materials sector is up 50.2 per cent over the same period, a sign that money has been rotating away from banks and toward resources.

Russel Chesler of VanEck said on Friday the sell-off could mark the beginning of a regime shift. He said Australian investors may need to look beyond the big banks to capture the next phase of opportunity on the ASX, arguing that the conditions that once made major banks the default trade have now reversed at the same time.

Chesler pointed to concentration risk in the majors, saying they had driven the index higher for years and could just as quickly drive it lower. He also warned that CBA alone makes up about 10 per cent of the S&P/ASX 200, and that when a single stock can move the benchmark by half a per cent on one quarterly update, a portfolio is no longer truly diversified.

VanEck said the old support for bank outperformance — disinflation, falling rates, steady housing credit growth and benign provisioning — has faded together. The firm said political debate over changes to capital gains tax discounts and negative gearing also spooked shareholders, while Australia’s mining sector has gained a durable tailwind from China cutting rare earth exports, the copper market and the global infrastructure cycle.

For now, the message from the market is blunt. The bank-heavy passive trade that carried Australian equities for years looks crowded and expensive, while the next phase of the ASX rally is likely to be narrower and more selective. Chesler said if geopolitical volatility eases and the earnings recovery broadens, Australia could still be one of the better risk-adjusted equity trades globally in the second half of 2026 — but only for investors willing to own the right parts of the market.