At what point in the history of the public markets in the United States was market-making of any sort not an activity reserved for an incredibly small minority?<p>The difference, from what I can tell, between the HFT &quot;elite&quot; and the human market-maker &quot;elite&quot; is that the human elite actively colluded to retain their status. Compare the largest HFT firms to the largest investment bank, and the number of entrances and exits in the market for electronic trading firs.