如何交易：在不同的外汇市场交易。

操作：那就看那个国家是行使浮率还是联系汇率制度，还有是否行使自由兑换汇率政策了。

1非自由兑换：由国家部门制定汇率在某个窄幅波动。汇率受和其他国家的双边关系影响。例子：中国

2自由兑换、联系汇率：由国家部门承诺当地货币和某个/某几个外币的汇率在某个水平窄幅波动，香港为例，金融管理局会动用外汇储备，在港元过高时卖出港元，买进美元；过低时买进港元，卖出美元，使汇率维持在7.8HKD/USD 左右。

3自由兑换、浮动汇率：汇率由市场上的供求决定，基本上没有人可以“稳定”汇率，政府的干预只能短期有效，长期还是由市场决定。

国际收支不平衡的问题：例子：In 1997, the United States ran a current account deficit and a smaller surplus in its capital account. As a result, the United States ran a surplus in the reserve account to balance the BOP accounts. A surplus in the official reserve account means that the US traded dollars for foreign currency. These official reserve balances are used by the Fed to intervene in the foreign exchange markets in an attempt to loosely control exchange rates.(例子来源：CFA study material)