My company is migrating from an older charting application to ExtJS4 and I am attempting to create a waterfall chart. My plan was to extend the series class, so that it acted mostly like a column chart except that I could adjust the Y-Position of each column individually (similar to ExtJS 3). Has this been accomplished already? If not, can someone tell me what config elements determine the bounding box of the columns? Are there any other config elements I will want to pay attention to in order to accomplish this?