Earlier this month Jamie Dimon said he was smarter than Donald Trump. Which suggests the JP Morgan boss is a lot less smart than he thinks he is.

Just consider for a moment. Dimon runs the biggest company in one of the most politically sensitive and heavily regulated industries in America and he thinks it is clever to belittle the president of the United States. And not just any president of the United States. The most thin-skinned and vindictive occupant of the White House in living memory.