The gross inequalities in income in the United States are hurting economic prosperity for everyone these days. When the rich have more money to invest, but everyone else has too little money to buy very much stuff, there's a huge risk that rich people's investments in new production will come to a halt because there's no one to buy all the things that the newest factories could theoretically produce. Therefore there's a risk of production in the real-world economy stagnating, for lack of good investment opportunities for the rich in new production. There will be also a risk of the richest investors turning to pure financial speculation, which can then lead as we saw during the time of the great recession, a huge speculative bubble in the economy
