The value of the Chinese currency Renminbi, or the yuan, has fallen against the U.S. dollar for five consecutive trading days. It weakened 13 basis points to 6.1189 against the greenback on Monday. It has fallen 136 points during the past five trading days, after dropping 20 basis points on Tuesday, dipping another 30 points on Wednesday, declining 43 points on Thursday and shedding 30 points on Friday, according to the China Foreign Exchange Trading System. Economists predict the depreciation may signal a change in China's exchange rate policy with increased two-way volatility ahead. The yuan depreciation is due to a combination of a USD-RMB exchange rate fix and concerns over China's growth outlook, they said. The yuan has dropped by more than 200 basis points against the U.S. dollar this year. In China's foreign exchange spot market, the yuan is allowed to rise or fall by 1 percent from the central parity rate each trading day. The yuan started rising against the U.S. dollar from 8.11 in July 2005, when China reformed its exchange rate mechanism. Appreciation quickened in 2013 and its value rose 3 percent, compared with 0.25 percent in 2012. In the past few days, both the daily yuan-against-the-U.S.-dollar fixing and the spot rate have weakened, causing a market stir. It is somewhat surprising given the stronger-than-expected January export growth rate and strong foreign exchange inflows so far this year, said Wang Tao, chief China economist at UBS. China's January exports surprised the market with a 10.6-percent rise year on year, far exceeding market expectation of less than 2 percent. Until recently, the RMB has appreciated steadily against the U.S. dollar, and with little volatility, Wang said.