The Price/Volume Trend Index ( PVT ) is a similar to On Balance Volume in that it is a cumulative momentum indicator which relates volume to price action. Whereas OBV provides a running total of volume and shows whether the volume is flowing in or out of a given security, the total volume used in the PVT calculation is dependent upon the relationship of Today's close to Yesterday's close.
An upward sloping PVT is generally bullish. Generally, the idea is that volume is higher on days with a price move in the dominant direction, for example in a strong uptrend more volume on up days than down days. So, when prices are going up, VPT should be going up too, and when prices make a new rally high, VPT should too. If VPT fails to go past its previous rally high then this is a negative divergence, suggesting a weak move.