According to a paper published last month by Christopher Reilly of Boston College, corporate bond ETFs listed in the US, on average, pay 48 basis points a year in hidden costs that result from custom creation baskets. Since most fixed ETFs track thousands of individual bonds, custom creation baskets allow issuers and authorized participants to create a sample of the holdings which mirror the performance of the ETF. An authorized participant is an organization, typically a bank, that manages the creation and redemption of ETF shares in the primary market. Without sampling, the authorized participants would have to source every security. However, the custom ETF creation baskets allow authorized participants more flexibility to include securities that could significantly underperform the underlying index. This customization results in hidden costs that investors of ETFs could incur.

Finsum: Corporate bond ETFs are paying an average of 48 basis points a year in hidden costs resulting from customized creation baskets.