In 1954 the economist Armen Alchian worked out which fuel powered the U.S. hydrogen bomb — by watching the stock market. Noticing that Lithium Corp of America’s shares had jumped about 461% that year, he deduced the secret was lithium. The government ordered his paper destroyed.

In 1999 a chimpanzee named Raven picked stocks by throwing darts at a list of 133 internet companies. Her “MonkeyDex” portfolio returned 213% that year — ranking her the 22nd best-performing money manager in the U.S. and beating thousands of professional brokers, before the dot-com crash wiped the gains out.

Wall Street’s "Charging Bull" statue was never commissioned. Artist Arturo Di Modica trucked it in and dropped it outside the NYSE overnight in 1989 as guerrilla art; the city kept it after crowds loved it.

U.S. stocks were priced in fractions until 2001. For two centuries a share might trade at 50 1/8, and the smallest possible move was an eighth of a dollar — a habit inherited from the Spanish “pieces of eight.” The NYSE only switched to decimals and penny increments in January 2001.