Investors beware: summer madness is here

So much of finance is automated these days you can forget quite how strongly markets echo human rhythms. Yet stock exchanges still ring their opening and closing bells at either end of the working day designed a century ago in Henry Ford’s car factory; the more civilised of them even break for an hour at lunch. The foreign-exchange market notionally operates around the clock, but it is a brave soul who attempts a big order during London’s early hours, before the City is open for business. And it is not just daily routines that matter—seasonal ones do, too. Spare a thought, then, for the 20-somethings left to run the northern hemisphere’s trading desks over the next few weeks, while their bosses doze on a beach.