South Sea BubbleSouth Sea Bubble, popular name in England for the speculation in the South Sea Company, which failed disastrously in 1720. The company was formed in 1711 by Robert Harley, who needed allies to carry through the peace negotiations to end the War of the Spanish Succession. Holders of £9 million worth of government bonds were allowed to exchange their bonds for stock (with 6% interest) in the new company, which was given a monopoly of British trade with the islands of the South Seas and South America.