Maybe we could use quantum entanglement devices to allow for faster trades? Since the speed of light in the medium is 0.66c you could probably get as close to c as possible.
But (as far as I understand) quantum entanglement doesn't let you transmit information at any particular speed, so that still doesn't work. (Roughly speaking, QE can be thought of as "the universe transmits information at >c", but in order to extract this information, we have to send messages conventionally. So it has a theoretical upper bound of c, like everything else, but has the same practical limits.)