Quote from your article:
>HFT greatly reduces average trading costs for investors
They are market-making, which is something else entirely than front-running.
They are market-making, which is something else entirely than front-running.
It's often claimed that HFT help make markets more liquid and efficient, "which helps everyone".
It's much less than clear whether the presence of HFT helps make an entire market more efficient, or whether just the HFTs are able to benefit.