Metric Insights includes the Highstock charting library and provides the ability to create any Highstock chart type. Below is one example. You can modify this chart to behave the way you want, and you can extend this library by adding other types of Highstock charts.
You can view more examples of Highstock Charts at http://www.highcharts.com/stock/demo/
Highstock compare multiple series
Highstock compare multiple series example