Vanguard Australian Shares Index ETF's 33% Bank Exposure Shifts Returns to RBA Cash Rate

VAS ETF investors see their returns tied to the RBA cash rate through the fund's heavy weighting in the bank sector. At the end of February 2026, approximately one third of the fund was invested in ASX bank shares, including Commonwealth Bank of Australia, Westpac Banking Corp, ANZ Group Holdings Ltd, and National Australia Bank Ltd. The fund tracks the S&P/ASX 300 Index, which contains significant bank exposure. This exposure is the mechanism by which a higher RBA cash rate increases the loan interest rate banks earn on transaction account balances, which pay little or no interest to customers. This increases the bank's net interest margin (NIM), which increases bank earnings. Because bank performance plays an important role in the index's overall return, increased bank earnings increase the overall return of the S&P/ASX 300 Index, which in turn increases the return for VAS ETF investors.