China's yuan dropped to its lowest level against the dollar in over four years Friday, as the central bank steadily guides the currency lower amid an economic slowdown and hefty capital outflows.

The as it's also known, fell to 6.4550 against the dollar, its lowest level since August 2011. Earlier Friday, the People's Bank of China (PBOC) had set the mid-point for the yuan at a new four and a half year low of 6.4358, down 0.2 percent from Thursday's fixing.