> making trades in the past The other posters' comments on QM are off the mark, this bit of TFA was a joke about special relativity. If you can transmit infor

> making trades in the past The other posters' comments on QM are off the mark, this bit of TFA was a joke about special relativity. If you can transmit information faster than the speed of light, there is an inertial reference frame in which that communication travels backwards in time, violating causality. (If the traders and the exchange are roughly comoving you won't see this effect, of course.)