In a recent analysis of exchange-traded funds (ETFs), a leading investment firm assessed the advantages and disadvantages of using ETFs compared to traditional mutual funds for passive equity investing. The firm noted that while passive ETFs offer lower expense ratios and greater tax efficiency due to their unique creation and redemption mechanism, there are specific scenarios in which ETFs might underperform relative to expectations.
Given this context, which of the following statements accurately captures one of the unique risks associated with investing in ETFs?