Not only does nanosecond resolution provide zero benefit, models indicate that it actually harms liquidity. To be specific, serial order processing in continuous-time is more efficient in "time-space", but less efficient in "volume-space". The better mechanism is batch order processing in discrete-time (i.e. process all arriving orders simultaneously in batch every 100 milliseconds, rather than one-by-one every nanosecond): http://faculty.chicagobooth.edu/eric.budish/research/HFT-Fre...