I am a believer in markets and generally buy the idea that HFT produces value by providing liquidity, but I interviewed at an HFT firm where we spent most of the time talking about microwave networks that cut down transmission times by nanoseconds. I have a hard time telling myself the story that an arms race over milliseconds is creating as much value as it captures. E.g. from WSJ:
> [Jim Barksdale] spent an estimated $300 million or more to bury a fiber-optic cable that shaved three-thousandths of a second off communications between New York and Chicago
> [Jim Barksdale] spent an estimated $300 million or more to bury a fiber-optic cable that shaved three-thousandths of a second off communications between New York and Chicago