What was the name of the 1720 English share-price collapse linked to the South Sea Company?

The 1720 English share-price collapse linked to the South Sea Company was the South Sea Bubble.

The South Sea Company received rights connected with British government debt and promoted expectations of enormous trading profits with Spanish America. Its shares rose spectacularly as investors, including prominent public figures, bought into the excitement.

The price surge was not supported by comparable commercial results. As confidence weakened, shares plunged, ruining many investors and creating a political scandal. Parliament investigated the company’s directors and allegations of corruption.

The South Sea Bubble is often discussed alongside John Law’s Mississippi Bubble in France, which also collapsed in 1720. They were separate schemes, although both became classic examples of speculative bubbles and helped shape later ideas about financial regulation.