Researching the usefulness of comparing s&p component stock prices to the price of SPY. Downloaded SPY and CAT prices from 1993 to present and divided CAT price by SPY price to get a percentage.
One thing that was noticeable right away: CAT as a percent of SPY increased from around 15% in 1993 to almost 75% today and has been as high as 86%--average is 33%.
Couple of questions: 1. am I wasting my time (common occurence) 2. If some of you think there is value to this study, how far back should I go to calculate an average? I'm thinking the last 12 months.