“Managers should not talk about people who work for them without those people in the room,” says the founder of what many describe as the largest hedge fund manager in the world, Bridgewater Associates.

Most managers will probably break this principle several times this week, and every week. However, they probably do not work at Bridgewater. The principle is one of 300 set out by Ray Dalio, the 61-year-old who founded Bridgewater when he was 25. The US company exhibits a sense of humour - its website has an introductory section that plays on its name comprising two nouns - but Dalio has made it clear he will not tolerate any manager who fails to adhere to this rule.