The Velocity Chart app displays trends in value delivery, including completed work not yet accepted. The volume of accepted work for an iteration is not updated in the Velocity Chart after the end of the iteration.
For example, if you accept a story or defect during the iteration and then re-open it after the iteration has ended, the Velocity Chart will not update with the corrected volume of accepted work in the past iteration. This may cause data in the Velocity Chart to be inconsistent with reports elsewhere in the application, such as the Iteration Status and Release Tracking pages, which display the volume of accepted work for an iteration and update that information based on changes that occur to work items after an iteration ends.
Data displayed in the app is in the same format as the Iteration Velocity chart. Select the chart to go to the Reports tab, where you may view additional information including a key and summary of velocity averages.
Velocity charts are dynamic. If you move a story out of the iteration after it ends, the results of the chart will change.