Why do we have a negative current in cyclic voltammetry curves?

Why do we have a negative current in cyclic voltammetry curves?
here are my thoughts. We have two conventions in reporting data of CV curves: the IUPAC convention and the US convention. In the IUPAC convention, the potential scan direction is from lower potential to higher and the US convention is reversed of the IUPAC convention (from higher potential to lower potential). So I think it's all about the direction of current in an electrochemical cell. because anodic current will be positive in the IUPAC convention and negative in the US convention. Therefore, maybe It does not relate to cathodic or anodic current. Can anyone explain more? what is the concept of the negative current?


