Observers in Hong Kong have long speculated on whether or when HSBC would relocate its headquarters back to the city. Now, to accelerate its so-called "pivot to Asia", three of its top executives are expected to move from London to Hong Kong. That is perhaps the next best thing for the global bank, which now wants to reinvent itself as a regional bank. Asia - specifically southern China - is where the real money is. The rest of the world has...