Crash Nº 3 · 1719–1721
The South Sea Bubble
A debt conversion becomes a national mania — Sir Isaac Newton included
−84% South Sea stock, June to December 1720
The Setup
London watched Paris mint millionnaires through 1719 with a mixture of horror and envy — the displacement here was partly Law himself. Britain’s version arrived dressed as public finance: the South Sea Company, whose trade with South America was mostly notional, offered to take over the unwieldy national debt, swapping government annuities for its own shares.
The arithmetic gave the scheme its engine. The conversion terms were fixed in nominal debt, so the higher the share price, the fewer shares it cost the company to retire each pound of annuities — the surplus shares were pure profit for insiders. Everyone connected to the scheme therefore needed the price to rise, and the company made sure it did.
Subscriptions ran on 10–20% down. The company’s in-house Sword Blade Bank lent cash against South Sea stock so buyers could subscribe again. Bribes in free shares seated the scheme comfortably in Parliament.
Displacement, winter 1719–20
The company outbids the Bank of England for the debt conversion, greasing the vote with share options for ministers. The stock, £128 in January, is already moving before the Act passes.
Boom, April–May 1720
Four subscription rounds on easy installments, plus company loans against its own stock, manufacture the demand the scheme’s arithmetic requires. Imitators multiply — bubble companies for insuring horses and “an undertaking of great advantage, but nobody to know what it is.”
Euphoria, June 1720
The stock touches £1,050 midsummer. Newton, who had sold in April at a solid profit, reportedly buys back near the top — the origin of his lament that he could calculate the motions of heavenly bodies, but not the madness of people.
Distress, July–August 1720
The Bubble Act — passed in June to protect the South Sea scheme from competitors — is enforced in August, and the writs prick the whole market. Investors selling rival shares to meet calls must sell South Sea too. The tide turns quietly, then all at once.
Panic, autumn 1720
September breaks the price from £775 toward £190; the Sword Blade Bank stops payment on the 24th, taking the credit machine with it. Goldsmiths and country banks fail down the chain. By December Parliament wants blood, and gets it.
The Reckoning
Parliament confiscated the directors’ estates, and Robert Walpole built a career — and effectively the office of Prime Minister — on screening the establishment from the fallout. The deeper legacy was the Bubble Act itself: England answered its first stock mania by outlawing the corporate form for a century. The pattern the book traces was already complete — including the reflex, after every crash, to ban the last bubble’s machinery rather than the credit dynamics beneath it.
What it cost
The Bubble hit a narrow band of people very hard. Hoppit’s count of the company’s four money issues in 1720 finds just under eleven thousand subscriptions taken, at averages between £3,359 and £8,569, at a time when a clergyman lived on about £60 a year. The restructuring that followed, on Velde’s figures, involved some 30,000 people in a country of 5.3 million. Britain did not suffer the Bubble. Particular Britons did.
- 17–40% lost by the government annuitants who exchanged their annuities for South Sea stock, measured to April 1723: 17–25% for the long annuitants, 24–40% for the short Velde, Britain’s Debt Restructuring, 1717–22, Federal Reserve Bank of Chicago working paper 2025-21, Table 7
- +40% suicides in London above trend in 1721, counted in the Bills of Mortality under its three headings for those said to have made away themselves, self murder’d or kill’d themselves Hoppit, The Myths of the South Sea Bubble, Transactions of the Royal Historical Society, 2002, from the London Bills of Mortality, with Macdonald and Murphy, Sleepless Souls, on what the surge meant
- 193 → 226 bankruptcies in England in 1719 and in 1721 — a rise, Hoppit notes, but hardly a meteoric one Hoppit, The Myths of the South Sea Bubble, Transactions of the Royal Historical Society, 2002
Some 20,000 people had swapped a government annuity for South Sea stock, and 2,000 of them signed a petition against the settlement Parliament was about to pass. In early August 1721 the annuitants, men and women, filled the corridors around the House of Commons handing out flyers, demanding justice “in a rude and insolent manner,” and tore the coat of a minister on his way in. Westminster’s justices read the Riot Act twice. One of the crowd shouted back that they picked people’s pockets and then gaoled them for complaining.
What followed
The Commons appointed a committee of secrecy in December 1720; it reported in February that the company’s books carried fictitious entries and that ministers had been paid in stock. John Aislabie, the Chancellor of the Exchequer who had carried the scheme through Parliament, resigned in January, was found guilty by the House in March of “the most notorious, dangerous and infamous corruption,” and was expelled and imprisoned. The directors’ estates were valued at £2,014,123; £354,600 went back to them to live on and the rest to the sufferers, which Velde notes came nowhere near covering the losses.
Encyclopaedia Britannica, 11th edition, 1911, South Sea Bubble; Velde, Britain’s Debt Restructuring, 1717–22, 2025