Which English company was at the center of the South Sea Bubble that collapsed in 1720?

The South Sea Company was at the center of the South Sea Bubble that collapsed in 1720.

Founded in 1711, the company received a British government monopoly over trade with Spanish South America in exchange for taking on government debt. In practice, its commercial prospects were far less impressive than many investors believed.

Speculation drove the share price sharply upward in 1720. The company also benefited from a debt-conversion scheme that encouraged holders of government debt to exchange it for shares. When confidence weakened, the price collapsed, ruining many investors.

The South Sea Bubble was part of a wider speculative episode. France's Mississippi Company experienced a related collapse, but it was a separate enterprise. The crisis also contributed to Britain passing the Bubble Act in 1720.