[Question] Should we create an EA index?

Apart from managing donations, how would it look if the CEA defined an EA500 index—similar to the ‘fortune500-index’ or the ‘S&P500-index’ upon which a non-profit index fund could be established to funnel investments to companies with a relatively high positive impact on the EA focus areas? In this way, return on investment could be reinvested into these same EA500-comanies or donated to the CEA. Where can I learn more about previous discussions on this question?