The ability of your mutual fund to provide low fee investments is directly related to their execution costs to trade to rebalance their portfolio.
Whether it is a direct line item on your prospectus or not is immaterial. No load mutual funds are more successful when they have lower execution costs. The biggest driver to low execution costs is an electronic market and then the bid/ask spread. HFT enable both of those low costs.
HFT doesn't enable electronic markets, it drives down the cost of them. The reason for this is that HFT participants are high volume users of electronic market infrastructure and have a vested interest in making that infrastructure cheap.
Whether it is a direct line item on your prospectus or not is immaterial. No load mutual funds are more successful when they have lower execution costs. The biggest driver to low execution costs is an electronic market and then the bid/ask spread. HFT enable both of those low costs.