How should investors “read” the pronouncements of Donald Trump? That question has prompted endless debate around the world in the past two years. But here is a new answer: try an Agatha Christie novel.

Yes, you read that right. Any fan of her mystery books knows that distraction is a powerful plot device: if there was a commotion in the kitchen, detective Hercule Poirot would look for a body in the library, or other clues being hidden in plain sight, amid the noise.

While Mr Trump has never admitted to be a Christie fan, his tactics — or instincts — might usefully be viewed in this light. Whenever the US president’s startling pronouncements create an attention-grabbing storm, investors must ask what bodies are being disposed of, amid the melodrama.