A single Highcharts chart with two stacked panes (a price line on the top y-axis and a volume column series on the bottom y-axis), made accessible by the MAIDR Highcharts adapter. The adapter detects the panes from the axis layout and emits one MAIDR subplot per pane: click on the chart, use Up/Down arrows to move between panes, press Enter to drill into a pane, and Escape to return to pane navigation.