I'm sorry, I didn't intend to put words in your mouth. I read your piece thinking it was going to present some justification for HFT. In your first paragraph you state that the point of this post is "merely an intellectual justification of a field which is often misunderstood." But then you don't directly justify HFT in the post, instead explaining the mechanics of HFT and market making. This is great; you explain it well.

However, I was still looking for the justification promised in the opening sentences. So I look for the subtext in your technical explanation that would justify this oft misunderstood field. I clearly misunderstood your justification for HFT. What is your justification for HFT?