China has been devaluing the yuan in the hopes of letting the general market play a larger role in currency markets. The yuan's value has fallen by about 3.5 percent since Monday.
Yesterday the People's Bank of China, which keeps tight control over the yuan, cut the daily reference rate by 1.9 percent, leading to the currency's largest single-day fall in over 20 years.
Analysts say that the devaluation will have a strong impact across Asia. Other countries, especially those that trade heavily with China, will likely cut their exchange rates.