In this note, we present a new point of view of how financial markets worked in nineteenth century in Spain, focussing on die price of money mobility, which is founded on the price of domestic bills of exchange on eight days' sight We reveal the source, then the conceptual framework in the use of the course of the exchange as the price of money mobility. Finally, we present a brief analysis of the course of the exchanges in Barcelona. Some conclusions are pointed out: the price of money mobility is a pivotal concept, since there is no doubt it had to have significant effects over both financial and real economy. High volatility of exchanges affects the financial economy while high values of them affects the real economy.