Its the internet you can do anything. Typically you will add a chart overlay to express to the user that data is not in the chart yet, data is loading or waiting to come back from the server.
We have a built in
nodata object which you can populate when the chart has no data.
For charts using our feed feature we have another object called
curtain to fill in the blank space on a chart.
If neither of the two demos above fit your use case you can of course use native browser techniques to accomplish a chart overlay.