The device that let strangers pool capital into a single enterprise by buying tradeable shares — spreading risk and raising sums no individual or partnership could. It built the great chartered trading companies, created the first secondary markets in shares, produced the first speculative bubbles, and bound the pooling of money to empire and colonial violence: ownership turned into a liquid, tradeable claim, and the form became the engine of both modern capitalism and armed corporate rule.
In 1602, a servant or a widow in Amsterdam could buy a slice of a company that sent ships to the far side of the world, and later sell that slice to someone else without dissolving the company. They never had to leave the city. This was new. For the first time, ownership of a great enterprise had been cut into small pieces that strangers could trade among themselves. Within two centuries the same instrument had funded private armies, helped conquer large parts of India, and produced the first great stock-market crashes. The question it raises has never gone away: when you turn a piece of a business into something anyone can buy and sell, what exactly have you set loose?