[cmdkeen]

It also very much depends on who is doing the investing. If you're CALPERs with ~$320bn you don't want to put it all into the S&P 500. Diversification through exposure to other, ideally uncorrelated, equity types or asset classes.

The best asset managers charge low fees, they make up for it very comfortably in volume and long term holdings. Warren Buffet famously doesn't sell, he doesn't need to make thousands of deals a year to eke a small profit from each, he needs to judiciously pick fewer things that are going to do well in the long term. All too often people don't want to properly invest however, they want to speculate.