Milton Friedman - In 1967, a Chicago bank refused a college professor by the name of Milton Friedman a loan in pound sterling because he had intended to use the funds to produce a shortage of British currency. Friedman, who had noticed that the pound sterling to be priced too high compared to the dollar, wanted to sell the coin and then, after the price of the currency declined, buy it back to repay the bank, staying thus pocketing a quick profit. The bank's refusal to grant the loan was due to the Bretton Woods Agreement, established twenty years earlier, which fixed national currencies against the dollar, and set the dollar at a rate of $ 35 per ounce of gold. after that spent several events that made the exchange of currencies are again a success and the creation of an online trade by mutually beneficial.