High-speed trading has been growing out of control in recent years—or at least, that's what it looks like from here. (I don't know anyone working in that sector of the industry at the moment.) Articles like this, this and this discuss the benefits and problems associated with practices such as co-location.
Assuming, for the moment, that it's unfair to permit such low-latency decision-making, how could a system be set up to keep bandwidth high, but make latency much less important?
What about saying "these trades will settle at an instant chosen uniformly at random from the next three seconds"? Would that make people unable to keep their latencies ultra-low more able to stay competitive in the market?