Such a big gain is certainly very eye-catching, but the real question is, if the private sector isn't suddenly scrambling to buy Yuan, why is the currency rising at the same time when the interest rates and the reserve ratio are being cut to support the economy? The only guess we can come up with is the IMF decision this month as a stronger currency is somehow seen as supportive of the application for an inclusion," said Sean Callow, senior Forex strategist at Westpac to South China Morning Post. 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.