$chart = new Highchart(Highchart::HIGHSTOCK);

$chart->chart->renderTo = "container";
$chart->rangeSelector->selected = 4;

$chart->yAxis->labels->formatter = new HighchartJsExpr(
    "function() {
    return (this.value > 0 ? '+' : '') + this.value + '%'; }");

$chart->yAxis->plotLines[] = array(
    'value' => 0,
    'width' => 2,
    'color' => "silver"
);

$chart->plotOptions->series->compare = "percent";
$chart->tooltip->pointFormat = "<span style=\"color:{series.color}\">{series.name}</span>: <b>{point.y}</b> ({point.change}%)<br/>";
$chart->tooltip->valueDecimals = 2;
$chart->series = new HighchartJsExpr("seriesOptions");