In 1815, the combined forces of Britain and Prussia defeated Napoleon’s army at the Battle of Waterloo. It was, said the Duke of Wellington, a damn close run thing. But even before the dust had settled on the battlefield, a carrier pigeon belonging to the House of Rothschild was on its way across the Channel to London. Nathan Rothschild, informed ahead of other traders that the country was not to be over-run by the French, consequently made a killing by buying British government bonds.

Little of this legend is true but there are elements that are accurate. There was a battle at Waterloo, which ended Napoleon’s career. Wellington did not say it was a damn close run thing but there is evidence he thought so. The Rothschilds used carrier pigeons but that was not how they learnt the battle’s outcome. Rothschild did have early knowledge of the outcome, and may have used it to advantage, but that knowledge was not the source of the house of Rothschild’s fabled wealth. It did, however, earn a great deal, helping governments of all complexions to fund the Napoleonic wars.

Financial markets have moved beyond carrier pigeons. The great financial centres of New York and Chicago are 700 miles apart. Fibreoptic cables transmit data between them in about seven milliseconds. But that is a long time in the life of a high-frequency trader, so Spread Networks has spent an estimated $300m building a fibreoptic link through the Appalachians. The shorter cable reduces the time taken to send data by about a millisecond.