Do you mean the market chart? This is where third-party controls come in
and there are lots of great charting controls out there.
One of the best in the business is Nevron Chart
(
http://www.nevron.com/Charting.aspx?nav=ChartDotNetNav&content=ChartDotNet)
Other good ones are from Infragistics (
www.infragistics.com), ComponentOne
(
www.componentone.com), ComponentArt (
www.componentart.com), Software FX
(
http://www.softwarefx.com/), Syncfusion
(
http://www.syncfusion.com/products/chart/web/default.aspx) to name a few.
There are inexpensive charting libraries out there, and some open source
ones as well, but sometimes with the free/less expensive libraries they
lack the visual elegance of the more expensive products.