Which 1720 company gave its name to Britain’s famous speculative stock-market bubble?

The South Sea Company gave its name to Britain’s famous 1720 speculative stock-market bubble.

The South Sea Company was founded in 1711 and received a monopoly over British trade with Spanish South America, although the expected commercial opportunities were far greater than the company’s actual business. In 1720, it proposed converting government debt into company shares, and promotional enthusiasm sent the share price soaring.

Speculation spread through London, including in newly formed ventures with little realistic commercial basis. Parliament passed the Bubble Act in June 1720, but confidence collapsed later that year. South Sea shares fell dramatically, ruining many investors and damaging the reputations of prominent figures, including Isaac Newton, who invested in the episode. The crisis was not simply a modern-style exchange crash: London’s financial markets were less formal, and the bubble involved debt conversion, monopolies, insider dealing, and intense promotion. The contemporaneous Mississippi Bubble in France was a related but separate episode.