labelFontSize: Number

Sets the font size of label (text) shown in Range Buttons in pixel.

Default: Automatically calculated based on StockChart size.
Example: 14, 16, … 
var stockChart = new CanvasJS.StockChart("container",
{
 .
 .
 rangeSelector: {
   buttonStyle: {
     labelFontSize: 16,
     .
     .
   }
 },
 .
 . 
});
stockChart.render();
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