South Sea Bubble
The British episode of 1720: a company granted a trading monopoly took on government debt and exchanged it for its own rising shares.
How to read the number
The scheme rested on that exchange — the dearer the share, the better the conversion terms, so the rising price was part of the design rather than a result of profit.
When the metric lies
The story is told as a parable about a gullible crowd, though its core is a state privilege and the interests of those who granted it.
Also known as: south sea company