Instead of the usual Volume chart below the Price Chart, Spark plots the volume bar of each period in 3 sections:
Blue – is the Active Bought Contract Volumes (where trade prices >= Ask)
Red – is the Active Sold Contract Volumes (where trade prices <= Bid);
Green – is the remaining contract volumes (where prices are between Bid and Ask)
The height of each bar (Blue-Green-Red) represent the total volume of that period, measured by the Right Axis
The white line represent the cumulative volume up to that period (measured by the Left Axis)
You can instantly change the period from 1-Minute to 5-Minute or even 15-seconds by clicking on the drop down list on the top.
You can also change the Period range and Bottom Axis (Time) Interval.
By using the left mouse button to drag on the chart from Top-Left to Bottom-Right, you can zoom any region on the chart.
Reversing the dragging will undo the zooming.
See next feature: Dual-Product X-Y Chart