The 1720 British financial bubble and crash involving the South Sea Company was the South Sea Bubble.
The South Sea Company received a government-backed plan to convert large amounts of British public debt into company shares. Investors were attracted by rising prices and promises connected with the company’s prospective trade with Spanish America, even though its actual commercial opportunities were much more limited than popular expectations suggested.
Share prices rose rapidly during 1720, encouraged by speculation and the creation of many other ventures. When confidence broke, South Sea shares collapsed, ruining investors and creating a political scandal. Parliament investigated the affair, and several directors and politicians were implicated in corruption.
The episode is often grouped with the Mississippi Bubble in France, which also burst in 1720, but they were separate schemes. Tulip Mania occurred in the Dutch Republic during the seventeenth century, so it predates the South Sea episode.