Those considered "too big to fail" are even bigger now.

Tax them. The purpose of a transaction is to support exchange of goods and services, not to shave commissions. Experts say we are less than 5 years away from fully computerized "trading" as an industry in itself with traders watching computers trading $ back and forth to other computers at quad-core speed, shaving every step of the way. That's crazy. So lets add a tax in there. Real businesses can built it into their costs for a one-off inflation (now would be a great time to do it) and it will disincentivize currency/asset movement for its own sake. Either that or establish a separate closed-system economy for this sort of speculation meaning that all losses, gains and commissions come from the participants in the game rather than from the wider community. Then you'd quickly see what is actually going on here. ;-)