> why we should build a system that enables HFT to be profitable.
because HFT's are more efficient. paying a guy to make a market in one stock is expensive. paying for a computer to do it is cheap. when the market maker's costs are lower, they can afford to quote tighter spreads and still be profitable. lower spreads => lower tcosts for "normal" (low frequency) market participants
because HFT's are more efficient. paying a guy to make a market in one stock is expensive. paying for a computer to do it is cheap. when the market maker's costs are lower, they can afford to quote tighter spreads and still be profitable. lower spreads => lower tcosts for "normal" (low frequency) market participants