Sometimes a market trader would put a cat in his bag and pretend it was a pig to fool the customer! So if someone lets the cat out of the bag, the secret would be open to us.

More likely, during the general election he will out-argue John McCain, a stout but not especially articulate free-trader, and nudge global opinion in a depressingly protectionist direction.

"If you take coal prices, chart them in euros and strip out the currency effect, you have a declining price," the trader said.