If so, then they should be disallowed. Regardless, they accounted for for a tiny fraction of all trading volume. I doubt most HFT firms make much from them. Say

If so, then they should be disallowed. Regardless, they accounted for for a tiny fraction of all trading volume. I doubt most HFT firms make much from them. Saying HFT is bad because of flash trading is like saying driving cars is bad because once in a while, someone dies from a car crash. The latter part is a true statement, but that's 0.01% of the picture. On another note, it should be pointed out that flash orders were created by EXCHANGES, not by demand from traders. The exchanges didn't want to have to route orders to other exchanges because of NBBO, so they offered this to traders hoping that someone would come fill the order at NBBO.