do you think that one reason why people say bad things about HFT is because they see them being unfairly compensated for taking on what they perceive is a small

do you think that one reason why people say bad things about HFT is because they see them being unfairly compensated for taking on what they perceive is a small amount of risk? I think that's definitely part of it. The issue is that people don't know how much high frequency traders actually make per contract. The amount is pretty small (on average). Typically, each trade takes on "bite-sized" risk and expects "bite-sized" returns. Do that thousands of times a day, and your bite-sized returns grow to something reasonable, but not ridiculous. Certainly, it's not on the order of how much other forms of proprietary trading make. I think the other issue is that people don't understand that all traders, HFT or not, take on risk when they enter a trade. A lot of people use terms like "skimming off the top" or "making money for nothing". This indicates to me that they don't realize why market makers should even make money (on average). It's simply risk transfer, and that has a price (on average). You're right though, identifying bona fide trends are pretty difficult. If it were easy, everyone would be doing it and arbing those trends away.