Laying this new fiber would probably be economically viable for low latency trading. They're already building microwave networks to take advantage of the spread

Laying this new fiber would probably be economically viable for low latency trading. They're already building microwave networks to take advantage of the spread between speed of light in air and glass (http://www.securitiestechnologymonitor.com/news/mckay-brothers-spread-networks-chicago-new-york-29829-1.html http://www.securitiestechnologymonitor.com/news/mckay-brothe...). Based on the fact that most long haul networks use fiber rather than microwave, I would assume that fiber is more economical than microwave.