Hello vandanamishra,
Some stack labels are not visible because of two reasons:
- first one is a bug which is reported here:
https://github.com/highcharts/highcharts/issues/16764
I have already implemented workaround in the demo that you can find below.
- second reasons is that stack labels are being hidden when there are not enough space to show them -
allowOverlap option should help.
Demo: https://jsfiddle.net/BlackLabel/e67bd1z9/
API reference: https://api.highcharts.com/highcharts/y ... lowOverlap
When it comes to 0, it is neither negative nor positive and because of that the label is positioned on the right side.
Let me know if you have any further questions!
Regards!