It’s often noted that actively managed equity mutual funds are less tax-efficient than equivalent passive equity ETFs/index funds but it’s rarely quantified. We sought to provide some data behind the realized after-tax returns for $1 million invested in a 1) highly ranked equity mutual fund and 2) comparable passive ETF to demonstrate the impact of taxes on total returns and investment gains over the 10 years ending in September 2021. While the pre-tax figures suggest the mutual fund performed better, the after-tax results might surprise you.