The IEX stock exchange uses fibre to introduce a fixed delay - https://en.wikipedia.org/wiki/IEX https://en.wikipedia.org/wiki/IEX "This 350 microsecond delay

The IEX stock exchange uses fibre to introduce a fixed delay - https://en.wikipedia.org/wiki/IEX https://en.wikipedia.org/wiki/IEX "This 350 microsecond delay adds a round-trip delay of 0.0007 seconds and is designed to negate the certain speed advantages utilized by some high-frequency trader" I watched this short video about it too - https://www.youtube.com/watch?v=d8BcCLLX4N4 https://www.youtube.com/watch?v=d8BcCLLX4N4