In July 2010 a trader named Anthony Ward bought 7 percent of the world’s annual cocoa production, pushed prices to a 33-year high, and earned the nickname Chocfinger. He was attempting one of the oldest and riskiest plays in commerce: cornering a market, gaining enough control of an asset to dictate its price. This episode explains why the strategy nearly always destroys the person who tries it. Buying on that scale inflates the price you pay, invites other traders to bet against you, and leaves you with a hoard you cannot sell without crashing the very market you built.

The history begins with Thales of Miletus, who rented every olive press around Miletus and Chios before a bumper harvest and proved a philosopher could get rich. It turns darker in the Gilded Age, when journalist Edwin Lefevre found vanity and revenge behind most corners. Jay Gould and James Fisk’s assault on gold produced the Black Friday panic of 1869, and F. Augustus Heinze’s failed copper scheme fed the Panic of 1907. Later chapters cover onions, the Hunt brothers’ silver, Sumitomo’s rogue copper trader, and Porsche’s secret move on Volkswagen.

• The Treasury broke the 1869 gold corner by releasing government gold. Gould and Fisk, tipped off early, sold out and escaped while ordinary investors were wiped out.
• Sam Siegel and Vincent Kosuga’s onion corner in Chicago led Congress to pass the Onion Futures Act, which still bans onion futures trading.
• The Hunt brothers drove silver from roughly $11 an ounce in the fall of 1979 to nearly $50 by January 1980. Exchanges then tightened margin rules and the price collapsed on Silver Thursday.
• Yasuo Hamanaka of Sumitomo controlled roughly 5 percent of the world’s copper for a decade through forged signatures and hidden positions, costing the firm $2.6 billion and earning him eight years in prison.
• In October 2008 Porsche revealed control of over 74 percent of Volkswagen through shares and options, and the resulting short squeeze briefly made VW the most valuable company in the world.