In fact 1973 marks the point to which nation-state, banking trade and controlled foreign exchange ended and complete floating, relatively free conditions of a market characteristic of the situation in contemporary times began (according to one source) 1, although another states the first time a currency pair were given as an option for U.S.A. traders to purchase was during 1982, with additional currencies available by the next year 2, 3.
On January the 1st of 1981 (as part of changes beginning during 1978 4) the Bank of China allowed certain domestic "enterprises" to participate in foreign exchange trading 5. Sometime during the months of 1981 the South Korean government ended forex controls and allowed free trade to occur for the first time. During 1988 the countries government accepted the IMF quota for international trade 6.
Intervention by European banks especially the Bundesbank influenced the forex market, on February the 27th 1985 particularly 7. The greatest proportion of all trades world-wide during 1987 were within the United Kingdom, slightly over one quarter, with the U.S. of America the nation with the second most places involved in trading 8.
During 1991 the republic of Iran changed international agreements with some countries from oil-barter to foreign exchange 9.