You're correct that without low-latency trading, markets will be less efficient in that bid-ask spreads will increase. However, I think of that efficiency as an

You're correct that without low-latency trading, markets will be less efficient in that bid-ask spreads will increase. However, I think of that efficiency as an architect optimizing a skyscraper's earthquake tolerance. Sure, on a regular day we want to save money, but a prudent person will "waste" on redundant systems and excessive tolerances.