Lack of regulations leads to monopolies. What’s better? Monopolies or Communism?

As the financial sector of the US continues pay government officials to loosen antitrust laws and buy up all the small broker firms and banks continue to merge there’s are now only a handful of gigantic financial institutions that just wait each other out until one collapses and is then quickly bought up by the last ones standing. Not very far off is the day that Microsoft will run all software and it will be financed by Goldman Sachs which will run all loans and it will be insured by AIG which will be the sole insurer etc… How long until they vie to buy each other? What is that called when a company instead of a government controls the means of production?