What was the name of the 1720 English company whose collapse helped define the South Sea Bubble?

The English company whose collapse helped define the 1720 South Sea Bubble was the South Sea Company.

Founded in 1711, the South Sea Company received a government-backed monopoly over trade with Spanish South America in exchange for taking on part of Britain’s public debt. The expected trading profits were much greater than the company’s actual commercial opportunities, but promotional claims helped drive intense demand for its shares.

In 1720, the company’s stock price soared as investors speculated and Parliament approved a plan connected with converting government debt. The price later collapsed, ruining many investors and causing a political scandal. The episode led to investigations and damaged confidence in joint-stock companies.

The South Sea Bubble occurred centuries before modern stock exchanges and electronic trading, but it displays familiar crash patterns: leverage, optimistic narratives, rising prices detached from realistic earnings, and panic selling. The contemporaneous Mississippi Bubble in France was a separate speculative crisis associated with John Law’s financial system.