Correlation coefficient of nearly 1 in a regression is not great. If the s&p returns swing up, and correlation not there, the return won’t be good. You really need it to be >1. I’m not an analyst nor an investor, just studied finance recently and find the topic interesting.
Discussion
You want the beta slope to be >1 in regression against s&p for capm. This tells you the change in the expected value of Yi corresponding to a 1-unit increase in Xi.
