I don't disagree with you here, but, on the other hand, parasitic trading [1] is a concept that's existed in market microstructure books for ages, since before

I don't disagree with you here, but, on the other hand, parasitic trading [1] is a concept that's existed in market microstructure books for ages, since before HFT. It is not clear to me why this happens, but the concepts of parasitic trading and high-frequency trading seem to be mixed up quite often, even though they are strictly speaking orthogonal to each other. It should still be possible to argue against parasitic trading that also happens to be high-frequency. [1] https://books.google.ca/books?id=Rd9hDRR1Yx4C&pg=PA195 https://books.google.ca/books?id=Rd9hDRR1Yx4C&pg=PA195