I want to plot the stock prices of certain companies VS the S&P500. I have all the price data downloaded in my excel sheet already. I want to create a line graph in Excel. One line is fixed and that would be the S&P500, and the other would be the company I select. I know how to use data validation to create a dropdown list, but how could I make it in such a way that when I select company A, I would only see company A's price data but not company B, C, etc. Then when I select company B, I would only see company B's price data & the S&P price data. And so on. The S&P line will be visible all the time, but the various company's price line will only appear if it is selected. Is there any easy way to normalize all sets of data in a way such that the starting point is always 100?