I would like to create an application where the user will be given the chance to choose two stocks (out of a selection of, say, 8 or 10 we shall offer) and watch their relative movement in time depicted on a bar, like the one attached.
For instance, before the open of every stock market session, the two - chosen by the user - stocks will be depicted next to each other on this bar (at 'point 0', so to speak). But then, when the session starts, they will move up or down, so the user will be able to see this 'relative movement' - their 'difference in performance', if you will - until the market closes and all action stops.