does anyone know of any trading platform, website, or charting software that will allow me to overlay a symbol onto a chart of a stock and have the it so they have the same starting point at the open? i've tried this on many software, but they always seem to start out at different places.

You could do this in amibroker but it would take a little coding. In amibroker you can plot not only a symbol but a formula. You can also plot as many additional symbols as you want on your chart using their foreign function. What you'd want to do is: -plot the original price of ticker1 -create a formula for ticker 2 using foreign * a factor which would normalize the two. For instance, if one starts the day at 40 and the other at 80, your factor would be .5 to bring the 2nd one into the same starting point as the first one. For someone that knows amibroker it would probably take only a little time (< 30 min) to set up. Hope that helps.

For each symbol you have to create the formula: a = the first data point in a series (minute, day, week, etc.) For each symbol: a/a going forward from a set datapoint (a/a, b/a - where b is the next data series, c/a d/a, etc.) I'm not sure live charting services can do it, but it's easy enough to do it in excell.

well i need it live because i daytrade. instead of nominal terms for the charts, i was thinking of % terms on the y-axis

Option 1: The most recent version of Quotetracker has this ability. I don't use it (the ability to compare unlrelated indicie) so I don't know how useful it is for trading ... Option 2: QuoteIn software can do this as a calculated value giving you a running total of the % Difference vs. the price at Open or any other set time period. Good Luck