“I always am skeptical of consequential arguments such as if HFT was not around how much worse off the world would be. I call it a "gun to the head" type of statement: don't do this or I'll pull the trigger. I always want to call the bluff.

“That said, Fidelity has announced an intention to build what I surmise will be an HFT safe zone trade exchange. If I were an HFT OK exchange I would be taking note.”

David Fuller's view

Good point.  Officials at too many exchanges rationalised HFT front-running because of their own short-term financial interests.