How can I get the max value of a y axis at highcharts?
i.e. http://jsfiddle.net/gh/get/jquery/1.7.2/highslide-software/highcharts.com/tree/master/samples/highcharts
Assuming that chart is your chart var.
chart.yAxis[0].max;
demo
Update
@Anagio told that it's possible to get it the following way.
chart.yAxis[0].getExtremes
This way you can get the data values and the tick values.
The data values are the values from your series, while the tick values are the values from chart lines.
Reference