Which British bubble burst in 1720 after rapid speculation in its shares?

The South Sea Bubble was the British stock-market bubble that burst in 1720 after rapid speculation in its shares.

The South Sea Company received a government-supported monopoly over trade with Spanish South America, although its actual commercial prospects were far more limited than many investors believed. In 1720, the company proposed converting part of the British national debt into company shares. Parliament approved the plan, and the stock price rose dramatically as investors chased expected profits.

The boom encouraged the creation of many other speculative ventures, including companies with implausible or deliberately vague business purposes. Parliament passed the Bubble Act in June 1720, restricting unauthorized joint-stock companies, but speculation continued. South Sea shares eventually collapsed, ruining many investors and causing a major political scandal.

The South Sea Bubble is often compared with the Mississippi Bubble in France, which also collapsed in 1720. They were separate schemes, however, managed by different companies and operating in different countries.