Which price axis a series maps to. 'right' (default) and 'left' each draw an
axis and autoscale independently; '' is a hidden overlay scale (no axis, its
own autoscale) used to pin a volume histogram inside the price pane.
overlay:name creates an independent scale, hidden by default and shared only
by series using that same name on this pane. Chart.setPriceAxisPlacement can
display an overlay or change any scale's side without changing its identity.
Which price axis a series maps to. 'right' (default) and 'left' each draw an axis and autoscale independently; '' is a hidden overlay scale (no axis, its own autoscale) used to pin a volume histogram inside the price pane.
overlay:namecreates an independent scale, hidden by default and shared only by series using that same name on this pane. Chart.setPriceAxisPlacement can display an overlay or change any scale's side without changing its identity.