The Chinese currency yuan, weakened 3 basis points to 6.9462 against the US dollar Tuesday, according to the China Foreign Exchange Trade System. 
In China's spot foreign exchange market, the yuan is allowed to rise or fall by 2 percent from the central parity rate each trading day, according to Xinhua. 
The central parity rate of the yuan against the US dollar is based on a weighted average of prices offered by market makers before the opening of the interbank market each business day.