Which theory was developed to justify investing joint-stock companies for the new world?

The theory that developed to justify investing in joint-stock companies for the New World is known as mercantilism. This economic theory emphasized the importance of accumulating wealth, primarily gold and silver, through a favorable balance of trade. It supported the idea that colonies existed to benefit the mother country, providing raw materials and markets for finished goods. Joint-stock companies allowed investors to pool resources and share risks, making it feasible to finance expeditions and settle new territories.