A horizontal histogram plotted on the chart of a security, which corresponds to the volume of shares traded at a specific price level. Price by volume histograms are found on the Y-axis and are used by technical traders to predict areas of support and resistance. |||Large price by volume bars are used to illustrate high buying and selling interest, and they are often regarded as a sign that the given price level will act as a strong area of support or resistance. It is common to see the price of an asset face little resistance when traveling between levels that have small PBV bars, but pushing the price past areas with large PBV bars is substantially more difficult.