# Changelog for Highstock v1.0.1 (2011-10-25)
        
- Added [series.compare](/stock/ref/#plotOptions-series--compare) option to compare the development of values.

## Bug fixes
- Fixed error on chart.addSeries.
- Fixed issues as listed at [GitHub](https://github.com/highcharts/highcharts/commits/master) under dates since the last maintenance version.