“Auto (fit data to screen)” is the default setting, so it will be selected by default. If that is unselected, that means the user has manually adjusted the scale of the chart. This could be because the user wants to focus on a specific range of prices, or because they want to see the chart in a certain way that the automatic scaling doesn’t provide. When you manually adjust the scale, the “Auto” option is automatically unselected to indicate that the chart is no longer being automatically scaled.
If you want to return to automatic scaling, you can simply select the “Auto” option again. This will reset the chart to fit the available screen space.
Please note that the default layout saves the settings as well.