total return % since purchase column in My Portfolio appears to be returning something much closer to the price return instead of total return (at least for VGT). Use of the same dates in the Graph shows total return correctly. To reproduce, put VGT in My Portfolio with a purchase date of 3/17/14 and look at total return % since purchase column value - this shows 831.33%. Create the same series in a graph which will show total return of 948.53% (the price return in graph will show 830.14%)