I seem to recall that the research on this says that HFT is actually a net taker of liquidity and that their profits are fully funded (and then some) by other i

I seem to recall that the research on this says that HFT is actually a net taker of liquidity and that their profits are fully funded (and then some) by other investors not really by making the market more efficient (they actually reduce efficiency). I've also heard stated many times that an exchange that only matches trades every X seconds would retain efficiency while eliminating HFT. This isn't the article I remember but goes into detail on most of these issues: http://www.demos.org/publication/cracks-pipeline-part-two-high-frequency-trading http://www.demos.org/publication/cracks-pipeline-part-two-hi...