Reminds me of this ramble https://nickbradbury.com/2014/12/11/the-programmers-dream-a-... . I printed it out and hung it in my livingroom, keeps me sane.
More pedantically, you're assuming those groups could take all of those assets from where the owners of those assets put them (including bonds, commodities, foreign investments, etc) and put them into the US stock market. Even if they did so they're barely above 50% of the US market cap (put at 25 trillion by World Bank).
http://data.worldbank.org/indicator/CM.MKT.LCAP.CD?locations...