Value Hotspot
A value hotspot is a non-visual element, which represents a rectangular area that includes a value marker and the area under the corresponding value point. The size of the value marker and the distance between a category axis and the value point determine value hotspot dimensions.
Value hotspots are used to determine whether a particular area corresponds to a data marker (for instance, when displaying value hints for chart values).
At design time you can highlight the borders of all value hotspots associated with a particular series by:
selecting this series within the Object Inspector or the Component Editor;
clicking within value hotspot areas of this series.