Yes, this is indeed true. Not sure why you're being downvoted. The distinction is still one worth making, because average retail investors can typically have be

Yes, this is indeed true. Not sure why you're being downvoted. The distinction is still one worth making, because average retail investors can typically have better transparency on this in a mutual fund vis-a-vis tracking error and management fees, whereas a retail trader in the open market is going to have almost no idea where the market really was for that market order they dumped into their Etrade account.