Use the HighLowLines property to display and modify the high-low lines that connect the highest and lowest values in each category. The stock charts display the high-low lines by default, so you can use this property to adjust their appearance, for example, to change the line color or width.
If you try to display high-low lines on a chart that does not support them, an exception occurs.
Currently, the SpeadsheetControl does not display the high-low lines on a line chart and does not allow changing the line properties on a stock chart. However, display settings are loaded and stored in supported formats, and you can modify them programmatically.