This process, technically know as issuing a trading statement, requires executives to achieve the tricky task of sounding incredibly smug and boring at the same time. The statements contain phrases such as "the board expects pre-tax profit to be in line with expectations", which really means "we're making a shedload of cash and you super-smart analysts were right to think so".
AMEC issued such a statement this week in which it said all was well in its world. It said 11 September had not "materially" affected the company and its order book was continuing to grow.
But as is often the case, there was bad news – and like others who have to break bad news, Amec put it in the middle of a long statement. The firm's sell-off of some US businesses will now cost £18m, up from the £10m predicted last year. The company's share price promptly fell 10p to 429p.
Any news like this inevitably forces share prices down, as investors work on the premise that it's always worse than the company initially predicts – and head for the door.