Currency War of 2009–11 dollar, with Goldman Sachs saying the real is the most over valued currency in the world. In October 2010, Brazil began increasing her capital controls, doubling a tax on foreign purchases of fixed-income assets to 4 percent so as to curb the real's appreciation to a two-year. On 18 October, Brazil sought to curb the real's gains by raising taxed capital inflow on fixed-income assets by 2% to 6% and taxed inflows for margin deposits on futures to 6% from 0.38%. Chile said it would implement capital controls to curb gains in the Chilean peso, which had strengthened the most
Currency strength indexes of this kind, major currencies are usually used because they represent up to 90% of the whole forex market volume. Currency strength is calculated from the U.S. Dollar Index, which is used as a reference for other currency indexes. The basic idea behind indicators is "to buy strong currency and to sell weak currency". If is X/Y currency pair is up trend, you are able to determine whether this happens due to X's strength or Y's weakness. With indicators of this kind one is able to choose the most valuable pair to trade; see the reactions of each currency