Even more than that. Going by their 2015 reports, KCG made $885M in revenue, and Virtu made $757M. JPMorgan made $93,543M. If you look at net income, it's even more dramatic since HFT firms generally run on tighter margins.

I've never quite understood the amount of HFT hate here. God's work it ain't, but it's a bunch of nerds using bleeding-edge technology and machine learning to break into and (dare I say) disrupt an industry whose avarice and sense of entitlement is perhaps unparalleled in modern history. It's tailor-made for this crowd, but somehow still gets a bad rap. I truly fail to see how that's less exciting than anything else anyone here gets worked up about.