javascript - Weird character in front of Highcharts tooltip series names -

i have highcharts chart is, reason, showing odd characters before series title on data point pop up. using default popup , highcharts 4.0.1.

i set series have title hi ensure nothing in code messing up. if output countsgraph.series[0].name hi.

what causing this? unfortunately cannot make fiddle @ moment access highcharts.com playing up.

here how create series

// create new series if requried if (!series[c]) {     series[c] = {         name: "hi",         data: []     }; }

enter image description here

most using different coding utf-8. can remove character, changing pointformat, from:

<span style="color:{series.color}">\u25cf</span> {series.name}: <b>{point.y}</b><br/>

to:

<span style="color:{series.color}">{series.name}</span>: <b>{point.y}</b><br/>

or, @adam goodwin pointed out, set default format in options:

<span style="color:{series.color}">\u25cf</span> {series.name}: <b>{point.y}</b><br/>

Brent