"The market" is a group of people who agree to a framework of trade, including laws and courts and an executive to enforce all that. Everyone who wants to be part of the market pays in (e.g. The US market requires you as a businees to pay US taxes; the EU the same).

Why people pay in is because by pooling resources, the collective group can set up a market much cheaper than each individual / company could do with each other.

Each collective group decides on how their market will be set up. The US is not quite the same as the EU, and different to China, for example.

Each market set up by the collective is socialism in action. The collective controls the market, not each individual in the market.