selected

Specifies whether the given point from the data series should be selected on the chart. Possible values are true and false (default):

dataSeries: [{
    data: [
        123.4, 71.5, 106.4, 129.2, 144.0, 176.0, 135.6, 
        {
            y: 216.4,
            selected: true
        }, 
        148.5, 216.4, 194.1, 95.6, 54.4]
}]

This setting is demonstrated in the following example.