Tonight at 7PM in Beijing, the People's Bank of China loosened its fixed-exchange rate against the dollar and instead pegged it to a basket of currencies.
This move is meant to cool the economy by strengthening China's currency, and it will affect those companies who have signed contracts pegged against the US dollar in China.
The yuan is now valued at 8.1 to the US dollar, and previously it was pegged at about 8.3. It is unclear exactly what currencies are being used, but most likely they include the euro, Japanese yen and other Asian currencies.