Hi Jack, at the bottom of the chart page is the data source. <A HREF="http://moneycentral.msn.com/investor/charts/charting.asp?Symbol=nat" target="_new">http://moneycentral.msn.com/investor/charts/charting.asp?Symbol=nat</A> The source is <A HREF="http://www.csidata.com/" target="_new">http://www.csidata.com/</A> .