随着美国经济在中国增长放缓和欧盟岌岌可危时缓慢增长，美元指数不断升值，截止到2016年7月的两年中上涨了21%。美元的强劲对全球经济产生了连锁反应，增加了以美元计价的债务成本并阻碍了全球贸易增长的速度，此外还降低了其他货币相对美元的价值。
越南盾
截止到2016年7月，越南的货币越南盾兑美元汇率大约为22376：1。这使越南盾成为美国承认的全球180多种货币中兑美元价值最低的法定货币。然而，一种货币相对另一种货币的强度只在判断从一段时间到另一段时间中该货币相对于另一种货币价值上升或者下降多少时重要。作为全球使用最多的储备货币，美元是进行这种计算时最受欢迎的交易媒介。尽管从2016年初到现在兑换一美元的越南盾数量增长了238，但是这只使越南盾兑美元的汇率从年初到现在下降1%。
委内瑞拉玻利瓦尔
同样，美元/玻利瓦尔的汇率也从年初的6.29上升到现在的9.98，导致玻利瓦尔相对美元贬值37%。这使玻利瓦尔成为2016年至今对美元最弱的货币。委内瑞拉货币贬值背后的原因是通胀水平的飙升，超过了700%，而且该国的经济不断萎缩，据预计将在2016年萎缩8%。这种货币和经济灾难导致了国内危机，粮食短缺的危机正在不断增长，导致该国30%的儿童营养不良并且辍学率不断增加。尽管官方的美元/玻利瓦尔汇率为9.98，但是在该国的黑市中一美元能兑换超过1000玻利瓦尔，这给委内瑞拉的危机做出了合适的描述。
英镑
尽管英国经济很健康，但是在其于2016年7月27日决定结束其43年的欧盟成员关系之后也遇到政治和经济危机。在退欧投票结束之后，英镑立即下跌11%跌到对美元的31年低点。巧合的是，英镑/美元的汇率也从年初到现在下降11%。退出欧盟使很多投资者对英国引发担心，因为该国的未来经济存在巨大的不确定性。惠誉国际评级和标准普尔都降低英国的主权债务信用评级。据预计英国退出欧洲经济联盟的过程要持续超过两年时间，这将给未来环境对国际经济和货币市场的影响带来更多的不确定性。
人民币
与英国相反，中国央行直接引发了人民币的贬值，使人民兑美元从年初的6.493增加到现在的6.683。在2015年将其外汇储备从2.62万亿美元削减到939亿美元之后，人民币/美元汇率下跌了7.5%，而从年初到现在下跌了3%。中国央行进行人民币贬值是为了通过使其货物以美元计价时更便宜从而增加出口。通过这么做，中国希望通过阻止其最大板块出口业的萎缩维持其GDP的增长。然而，人民币贬值增加贸易有引发货币战争的风险，货币战争是指出口依赖型国家竞争性贬值、损害全球经济。
Weakest Currencies Against the U.S. Dollar in 2016
By Chase Carmichael | August 29, 2016 — 12:51 PM EDT
As the American economy slowly strengthens amid weakening growth in China and a fragile European Union, the U.S. Dollar Index has appreciated in value, rising 21% over the span of two years, as of July 2016. The robust greenback has had a ripple effect through the global economy, raising the cost of dollar-denominated debt and stalling international trade growth, in addition to depreciating the value of other currencies.
Vietnamese Dong
As of July 2016, the currency of Vietnam, the dong, was valued at roughly 22,376 units per U.S. dollar. This makes the dong the weakest medium of exchange out of the 180 total currencies internationally recognized as legal tender by the United Nations. However, the value of a currency relative to another is only important as a gauge to how much that currency has strengthened or weakened relative to the other currency from one point in time to another. As the most frequently used reserve currency of the world, the U.S. dollar is the most popular medium of exchange to use when making such calculations. Although the amount of dongs per U.S. dollar has risen by 238 since the start of 2016, this is only a 1% year-to-date (YTD) drop in the VND/USD exchange rate.
Venezuelan Bolivar
Comparably, the U.S. dollar-to-Venezuelan-bolivar exchange rate has risen from 6.29 to 9.98 YTD, resulting in a 37% depreciation of the bolivar relative to the greenback. This makes the bolivar the relatively weakest currency to the U.S. dollar for 2016 thus far. The weakness behind Venezuela's currency has been fueled by surging levels of inflation, greater than 700%, and a contracting economy that is predicted to shrink by 8% in 2016. This monetary and economic calamity has led to a domestic crisis where the severity of a food shortage grows every day, leaving 30% of children malnourished amid a rising rate of school absences. While the official USD/VEF exchange rate is at 9.98, in the country's thriving black market, a dollar is worth more than 1,000 bolivar, giving proper illustration to the extent of Venezuela's crisis.
British Pound
Despite a healthy economy, the United Kingdom has experienced its own political and currency crisis, following the decision to sever its 43-year EU membership on June 27, 2016. Immediately after the Brexit vote, the pound fell 11% to a 31-year low relative to the U.S. dollar. Coincidentally, the GBP/USD exchange rate is also down 11%, YTD. Such a monumental move in exiting the EU has left many investors wary of Britain, due to enormous uncertainties facing the country’s future. Both Fitch Ratings Inc. and Standard & Poor’s have downgraded Britain's sovereign debt ratings. The process of exiting the European economic union is expected to last more than two years, bringing more uncertainty to how the situation may influence the international economy and currency markets of the future.
Chinese Yuan Renminbi
Contrary to Britain, the People's Bank of China (PBOC) has directly caused the devaluation of its currency, the Chinese yuan, from 6.493 units per U.S. dollar to 6.683 YTD. After reducing its foreign-exchange reserves by $2.62 trillion to $93.9 billion in August 2015, the CNY/USD exchange rate has since dropped by 7.5% over the past 11 months and by 3% YTD. The PBOC has devalued its currency to increase exports by making them cheaper in terms of the dollar. By doing so, China hopes to maintain its gross domestic product (GDP) growth by preventing the contraction of its largest sector, exports. However, devaluing the yuan to increase trade runs the risk of beginning a currency war, where export-dependent countries competitively devalue their currency, damaging the global economy in the process.
本文翻译由兄弟财经提供
文章来源：http://www.investopedia.com/articles/trading/082916/weakest-currencies-against-us-dollar-2016.asp