Which 1720 speculative collapse is often considered the first modern stock-market crash?

The 1720 speculative collapse often considered the first modern stock-market crash was the South Sea Bubble.

The South Sea Company was granted a monopoly over British trade with Spanish South America, although its actual trading prospects were far less impressive than public enthusiasm suggested. Its shares rose dramatically in 1720 as investors expected extraordinary profits.

The company’s share price reached about £1,000 in August 1720 before collapsing by the end of that year. Many investors suffered major losses, and the scandal damaged public confidence in financial promoters and political figures connected with the company.

The South Sea Bubble unfolded alongside John Law’s Mississippi Bubble in France. The two episodes are related examples of early eighteenth-century speculation, but they were separate companies and markets.