Contract Law != Markets. It can certainly be pushed onto the runway. Whether it flies or not depends on whether anyone wants to buy it, and that depends on whe

Contract Law != Markets. It can certainly be pushed onto the runway. Whether it flies or not depends on whether anyone wants to buy it, and that depends on whether what's behind it is worth buying. All markets do is find a price for you based on supply vs demand (with some complexity due to monetary distribution behind the scenes.) There is nothing stopping startups coming up with their own forms of share holding (cf facebook for example). In general the ones that will be able to pull it off will be the ones everybody wants to own a piece of. All contracts are after all is an agreement between two parties - in this case, copied and pasted from extremely hazardous shipping agreements used in 18th century when the chances of a ship coming back at all weren't that good, press gangs were being used to crew naval shipping, and the entire clearing system for the London Banks was being run by their clerks in a backroom bar in a pub on Lombard st. Times change. It took them fifty years, but eventually the bank managers noticed.