What was the name of the speculative bubble that collapsed in London in 1720?

The South Sea Bubble was the speculative boom and collapse surrounding the South Sea Company in Britain in 1720.

The company received rights connected with British trade in the South Seas and converted government debt into company shares. Excitement about trading opportunities helped drive its share price dramatically higher. Investors included prominent figures, and the enthusiasm spread beyond the company itself to other ventures.

When confidence weakened, the share price collapsed. The crisis ruined many investors and caused a political scandal because influential people had promoted or benefited from the scheme. Parliament investigated the company, and several directors faced serious consequences.

The South Sea Bubble is often discussed alongside France’s Mississippi Bubble, which also burst in 1720, but they were separate schemes. Neither event was a modern stock-market crash in the electronic sense; both were early examples of securities speculation, leverage, promotional hype, and contagious loss of confidence.