On Balance Volume (OBV)

One of the first and most popular indicators to measure positive and negative volume flow, the OBV was introduced by Joe Granville in 1963. The concept behind the indicator is that volume precedes price. OBV is a simple indicator that adds a period's volume when the close is up and subtracts the period's volume when the close is down. A cumulative total of the volume additions and subtractions forms the OBV line. This line can then be compared with the price chart of the underlying security to look for divergences or confirmation.