The land-bankers’ argument that value was an extrinsic quality – subject to changing “opinion and fashion” – was particularly relevant to the stock market, since from the launch of diving companies onwards the market had fallen for a succession of fads. The rise of the stock market in the early 1690s was accompanied by a fashion for increasingly extravagant ladies’ headdresses, which climbed in height from the early 1690s until they peaked at over seven feet in 1695 (the year the stock market crashed). This prompted Sir Richard Steel to remark that “Stocks have risen and fallen in proportion to headdresses” – an observation which anticipates the connection between women’s rising hemlines and the stock market in the 1920s (what has become the “hemline theory of stock prices”). In 1919 the average level of the hem above the ground was 10 percent of a woman’s height. In 1920, during the postwar recovery, the hemline rose to around 20 percent. In the recession of 1921, it fell back to around 10 percent. As the bull market took off in 1924, hemlines rose until they reached 25 percent, in 1927, at which point they met the knee. They remained there until late 1929. After the Great Crash, hemlines fell until with the onset of the Great Depression they brushed the ground.

According to the text, the “hemline theory of stock prices”