Question

See this fiddle: http://jsfiddle.net/ebuTs/13/

How to make the dots (points) bigger?

Answer 1

You can play around with the marker radius:

var chart = new Highcharts.Chart({
//...
    series: [{
        data: [29.9, 71.5, 106.4, 129.2, 144.0, 176.0, 135.6, 148.5, 216.4, 194.1, 95.6, 54.4],

    marker: {
        radius: 5// Play around with this value as needed.
    }