South Sea Bubble (1720)

Overview

The South Sea Company was a British joint-stock company founded in 1711 as a public-private scheme to convert and manage a portion of the government's national debt, in exchange for which it received a monopoly on British trade with Spanish South America — including, from 1713, the asiento de negros, a thirty-year contract to supply Spanish colonies with enslaved Africans.[1] Actual trade profits were minor; the company's business was overwhelmingly financial, converting government annuities into company shares. Company stock rose sharply through the early months of 1720 as investors speculated on future profits, reaching roughly ten times its face value by summer, before collapsing to little above its original price by the end of the year — ruining thousands of investors, including, famously, the physicist Isaac Newton, who is reported to have lost on the order of £20,000 after re-entering the market near its peak, having earlier sold at a profit.[1][2] Newton is often quoted as saying he "could calculate the motions of the heavenly bodies, but not the madness of people"; modern scholarship treats this anecdote as resting on thin and partly secondhand evidence rather than a contemporaneously documented remark.[2]

The Georgist Reading

Fred Harrison's Boom Bust: House Prices, Banking and the Depression of 2010 (2005) opens its historical account of securitisation — the capitalising of a future income stream into a present-day tradeable asset price — with the South Sea Bubble, describing it as an early instance of the same mechanism Harrison traces through to the sub-prime mortgage securitisation that preceded the 2008 financial crisis.[3] On Harrison's reading, the underlying asset being capitalised in 1720 was a bundle of monopoly trading and debt-conversion rights rather than land specifically, which makes the episode a precursor case for the broader boom-bust pattern rather than a land-cycle episode in the narrower sense used elsewhere on this wiki.[3] This framing is Harrison's own; standard financial-history accounts of the South Sea Bubble emphasize stock manipulation, insider dealing among company directors and government ministers, and the absence of any effective securities regulation, rather than a rent-securitisation thesis specifically.[1] The most-cited modern economic-history treatment, Peter Temin and Hans-Joachim Voth's "Riding the South Sea Bubble" (American Economic Review, 2004), likewise reads the episode through investor behaviour rather than any capitalisation-of-rent mechanism: using a unique daily-trades dataset from Hoare's Bank, they argue "it was profitable to 'ride the bubble'" and that "the need for coordination in attacking the South Sea bubble was the key to allowing it to inflate to such an extreme extent," with Hoare's making "a profit of over £28,000" even as "many investors, including Isaac Newton, lost substantially in 1720."[4]

See Also

• Boom-Bust Cycle — the general concept of asset-price cycles Harrison situates this episode within
• Harrison, Boom Bust (book) — the discovery source for the securitisation framing
• 2008 Financial Crisis — the modern episode Harrison connects the South Sea Bubble to
• Land Bubble — the related concept for asset-price speculation in land specifically

Sources

1. "South Sea Company," Wikipedia, accessed July 2026 — used for the company's founding, the debt-conversion structure, the asiento slave-trade monopoly, and the 1720 share-price rise and collapse. Wikipedia
2. "Isaac Newton's financial misadventures in the South Sea Bubble," Andrew Odlyzko, Notes and Records: The Royal Society Journal of the History of Science 73(1), 2019 — used for Newton's estimated losses and the scholarly caution around the "madness of people" quotation. Royal Society
3. Fred Harrison, Boom Bust: House Prices, Banking and the Depression of 2010, Shepheard-Walwyn, 2005, Ch. 7 §1 — the discovery source for this page; used for the framing of the South Sea Bubble as the founding episode in a securitisation pattern running through to sub-prime mortgages, drawn from the wiki's existing discovery-report summary of the book rather than a fresh primary-text read. The Ch. 7 locator is therefore provisional; the page's factual and economic-history claims rest on sources 1, 2 and 4 rather than on Harrison's text.
4. Peter Temin and Hans-Joachim Voth, "Riding the South Sea Bubble," American Economic Review 94, no. 5 (2004): 1654–1668 — the standard modern economic-history study; used for the "ride the bubble" thesis, the coordination-of-attack argument, Hoare's Bank's ~£28,000 profit, and Newton's substantial 1720 loss (Temin and Voth cite John Carswell's The South Sea Bubble for context). Quotations taken from a fresh read of the full-text working-paper version. PDF (CREI/UPF)