Mutual funds that buy and sell stock incur costs on these transactions. These transaction costs are not included in a fund’s expense ratio. Transaction costs include brokerage commission expense, buy and sell spread costs, and market impact costs, Among these costs, only brokerage commission costs are reported. These costs are recorded in the N-CEN report. We can take this expense and divide it into a fund’s average net assets to produce a commission expense ratio, analogous to a fund’s reported expense ratio. This blog entry will examine the brokerage commission expense of Vanguard active and passive funds from 1994 to 2019.