Sorry the scaling of the bigcharts converges the last price of...

Sorry the scaling of the bigcharts converges the last price of both the heads and options onto the same chart spot.. It shows the history as a much wider deviation..It didnt do what I was hoping... by showing changes of difference, I was under the impression that options would separate more closer to strike date if they were not likely to be taken up and show a price decay...
I was looking for any leads? arbitrage differences of either instrument...
hope that makes a bit of sense...Please shut me up If that sounds like Im just Barking....
There is a TA method of calculating the relative strength comparisons to show what Im after..