Innovation & Wealth › Trading companies & early capitalism
South Sea Company and its bubble
company 1711; bubble and crash 1720· Event· Companies & fortunes
Well documentedSolid records, texts or physical evidence.
A British company formed in 1711 to take on government debt, whose share price rose about eightfold in 1720 before collapsing.
See it on the Innovation & Wealth map →What happened
Tory minister Robert Harley set up the company to absorb about £9 million of government debt, offering monopoly trade with Spanish America; after 1713 that meant mainly the Asiento slave contract. In 1720 it offered to convert most of the national debt into its shares. Bribed ministers backed it; shares rose from about £128 in January to over £1,000 by June, then sank below £200 by autumn. Some holders, like bookseller Thomas Guy, sold early; Isaac Newton reportedly lost heavily.
Impact on society and the economy
It made 'bubble' the word for manias and produced the Bubble Act. Robert Walpole's cleanup kept the debt conversion, lowering government interest costs, while late buyers took the losses.
How we know
Twice-weekly share prices in John Castaing's Course of the Exchange, Parliament's 1721 Secret Committee report on bribery, company records, and William Hogarth's satirical print The South Sea Scheme (1721).
Still debated
Whether buyers were simply mad or making rational bets on a debt deal is debated; Newton's famous quote about 'the madness of people' is poorly sourced.
Inside this (2)
Connections (5)
▸South Sea Company and its bubble began as a rival scheme to Bank of England and the national debtMostly agreed
The connection
The Bank of England was closely tied to the Whigs. In 1711 Tory minister Robert Harley created the South Sea Company as a rival vehicle for government debt. In 1720 the two bid for the national debt; the South Sea Company won by offering up to £7.5 million. Losing the bid spared the Bank the worst of the crash.
When and how
London, 1711 and January–February 1720; Robert Harley, South Sea director John Blunt and the Bank's directors, bidding before Parliament.
How sure are we?
Parliamentary records of the 1720 bidding contest, and P. G. M. Dickson's history The Financial Revolution in England (1967).
Debates
How much the rivalry was party politics, versus straightforward competition for profitable debt business, is debated.
▸John Law and the Mississippi Bubble ran the French twin of South Sea Company and its bubbleWell documented
The connection
Law's Mississippi Company swapped French government debt for soaring shares in 1719. British ministers feared France would shed its debts and gain an edge, and the South Sea Company copied the debt-for-equity swap in 1720. Money and speculators moved between Paris and London; Law's system cracked first, and the South Sea boom collapsed months later.
When and how
Paris and London, 1719–1720; John Law, the regent Philippe d'Orléans, South Sea director John Blunt, and British ministers.
How we know
Contemporaries compared the schemes directly, and price records show the Paris peak around January 1720, followed by London's in June.
Debates
Whether capital flowing from Paris fueled the London boom, as historian Larry Neal and others discuss, and how directly Blunt copied Law are debated.
▸Bubble Act was passed partly to protect South Sea Company and its bubbleWell documented
The connection
Dozens of unchartered companies were selling shares in 1720, competing with South Sea stock for investors' money. The Act, passed in June with the company's support, outlawed such firms. In August the company had writs issued against several rivals; the selling that followed spread to its own shares and may have helped start the crash.
When and how
London, June–August 1720; Parliament, South Sea directors, and rival firms such as the York Buildings Company.
How we know
Parliamentary journals, the August 1720 legal writs, and studies by Ron Harris and others of the Act's origins.
Debates
Historians disagree whether the Act was mainly South Sea lobbying or a genuine anti-fraud measure, and whether the writs truly triggered the crash.
▸South Sea Company and its bubble held the Asiento slave contract in Sugar plantations and the Atlantic slave tradeWell documented
The connection
The 1713 Treaty of Utrecht gave Britain the Asiento, a 30-year contract to supply 4,800 enslaved Africans a year to Spanish America, and the government assigned it to the South Sea Company. The company shipped tens of thousands of captives, often via Jamaica, until wars with Spain disrupted the trade; it gave up the contract in 1750.
When and how
Treaty of Utrecht, 1713; deliveries to Cartagena, Veracruz, Buenos Aires and other Spanish ports, mainly 1714–1739.
How we know
The treaty text, company records and the SlaveVoyages database; Helen Paul's 2011 study shows the slave trade was a real part of the business.
Debates
Whether the slave trade made money for the company is debated, as is how much it figured in investors' expectations in 1720.
▸South Sea Company and its bubble was echoed a century later by Railway ManiaMostly agreed
The connection
Both manias followed the same pattern: a new opportunity, easy credit, shares bought on small deposits, a rush of promoters, then collapse. In 1720 South Sea stock rose about eightfold before crashing; in 1845 railway shares soared, then fell by more than half. Commentators in the 1840s invoked 1720 as a warning.
When and how
London's stock market, in 1720 and again in 1844–1847, about 125 years apart.
How sure are we?
Share-price records show similar boom-and-bust shapes, and 1840s newspapers compared the two directly; the link is a parallel, not a direct cause.
Debates
Charles Mackay's 1841 bestseller retold the South Sea story, yet he backed railways. The South Sea scheme built nothing, while railway money left real track.