> he traits to categorize are it's rigged, parasitic on others
I'm not sure that's a good way to frame them. If you frame them as parasitic, then the argument shifts towards how we can stop them, as they don't provide any value. HFT firms do provide value in liquidity and more accurate market prices. Whether the cost them impose for these is worthwhile is an open question, but then the argument is about how to tweak incentives and rewards to best utilize this resource, not how to prevent it from working at all. The framing matters.
I'm not sure that's a good way to frame them. If you frame them as parasitic, then the argument shifts towards how we can stop them, as they don't provide any value. HFT firms do provide value in liquidity and more accurate market prices. Whether the cost them impose for these is worthwhile is an open question, but then the argument is about how to tweak incentives and rewards to best utilize this resource, not how to prevent it from working at all. The framing matters.