But here's the thing.. The money is circulating for no particular reason. There are not goods and services being exchanged in the frequent trading financial sector.
The money is circulating for very good reasons. Companies with revenue in one currency are hedging against expenditure in another, insuring debt, hedging fixed term interest rates against floating rates, primary producers are hedging their crop prices, miners are hedging the price they receive for what they mine and so on.
Granted, there are a lot of speculators out there. But most financial instruments out there were invented to mitigate risk and for hedging (ok, maybe CDOs were just invented to make money!).