It seems that using BarGraphItem or FillBetweenItem prevents the auto-scaling of the visible-data-only in plots. To reproduce, use the FillBetween example in the pyqtgraph.example demo -- if one sets autoscale to visible data only on the full data set, the y-axis maximum rattles around between about 8 and 12. But if one pushes most of the full data set out of the visible window and just looks at one side of the other, and resets the settings to auto-scale visible-data only, the y-axis is still maximum of 8-12, not something more appropriate for the reduced data span at the beginning or end of the data set. The apparent disabling of the visible-data-only autoscaling occurs even when I add a regular plot curve to the bar data.

Curiously, the CandlestickItem used in the Custom Graphics Example (which I adapted slightly to allow for the close == open) will auto-scale very nicely.

Perhaps all graphics objects need a "boundingRect" function like CandlestickItem has?