The On-Balance Volume (OBV) is a momentum technical indicator that relates volume to price change. This indicator was introduced by Joseph Granville. OBV is considered to be a pretty simple indicator. If the closing price of the current bar is higher than the previous closing price, the volume of the current bar is added to the previous volume of OBV. If the closing price of the current bar is lower than the previous closing price, the current volume is deducted from the previous volume of the balance.