You might want to look at private trading markets. It is sort of a lower scale version of the public markets. Companies can be traded between entities as stock

You might want to look at private trading markets. It is sort of a lower scale version of the public markets. Companies can be traded between entities as stock without the onerous accounting requirements but there are certain stringent requirements. There can be at most 400 share-holders and the deal killer -- stock holders have to be institutional investors with over $100 million in assets. If you have that much cash, you may as well become a VC. I am not an expert on this so independent checking on this would be nice. To my knowledge, NYSE and GS have setup something like this.