In Constant Volume Bars (CVB), a new bar is created each time Volume exceeds a particular value. For instance, if the cutoff value was specified to be 250 million shares like shown on Figure 1 (below), a new bar is added to the chart.
 CVB in action |
Right-click the chart and select "Chart Style Settings" - or simply hit Ctrl-Y on your keyboard - to invoke the dialog where you can set the volume cutoff for creation of a new bar (threshold). The other option ("Continuity") controls the CVB visualization style.