By default, the UpdateOnMoving property is True. You can use this property on False, to prevent moving/updating all related bars while moving/resizing the current bar. For instance, if you are moving a summary bar, all related child bars are moved together, which could be a time consuming, if having thousand of child bars. Using the UpdateOnMoving property on False, the summary bar will be single moving, and once the user releases the mouse, all related bars takes their new positions.