text:  Theo, what's been the impact on markets? Well, it depends which market you're talking about. So if we talk about the London stock market, on the face of it, the impact hasn't been too severe. Shares have fallen, but not by a huge margin. But when you look into it, certain sectors have been hit very, very badly. So you've probably been hearing how flights have been delayed and cancelled around the world. People haven't been able to go on holiday or haven't been able to get to business meetings. They've had long waits.