[Solved]-How do I hide a Highcharts series from the chart, but always show it in the tooltip?-Highcharts

at this point if the rates are only a series to make it into the tooltip, i'd just scrap the series all together and include the data via the formatter. something like:

var rates = {'category1':20,
             'category2':25,
             'category3':75};

...

tooltip: { shared: true,
     formatter: function() {
          var s = '<b>'+ this.x +'</b><br/>';                
          $.each(this.points, function(i, point) {
              s += '<span style="color:'+point.series.color+'">'+point.series.name+'</span>: <b>'+point.y+'</b><br/>'
            });
            s+='rate: ' + rates[this.x] + '%';
            return s;
        },
 ...

updated fiddle here.