MS Queen Victoria, 38°N 19°E

I’ll do my best, but I’ve got to be honest: being surrounded by shining Ionian waters and convivial Spectator cruisers isn’t helping me channel the panic that has gripped global markets. So forgive me if this dispatch doesn’t have the apocalyptic tone you’re expecting. I’m as irritated as anyone that contagion from China’s share-gambling epidemic has knocked my modest interest in FTSE100 stocks back to where it stood in late 2012, but ask yourself: do you know anything about China or the global economy today that you didn’t know a month ago?

Markets have overreacted, on relatively...