Extrapolation can be a dangerous thing. Investors have set Australian iron ore stocks alight in the five trading days since Rio Tinto walked away from Chinalco – perhaps reasoning that there is about $20bn in committed capital just waiting to be put to work. Fortescue, a distant world number four in iron ore with a market capitalisation of $11bn, said it had no clue why its shares were up more than a fifth yesterday.

Cooler heads should prevail. Chinalco’s move on Rio was a multi-act affair, plotted long before its dawn raid almost 18 months ago. It is unlikely to strike on the rebound, while emotions are running high: commentators at the official Xinhua news agency have rued Rio’s “perfidy” in “kicking down the ladder”.