At times, the financial industry can appear like a study in perpetual motion – always developing, never standing still. The five-year anniversary of the collapse of Lehman Brothers reminds us that banking empires can crumble and new orders can be established in the blinking of an eye. Fads can flare up and then fizzle away just as quickly (anyone remember 130/30 funds?).

But equally, some issues endure longer than others; some predictions are always on the verge of coming true. These are the hardy perennials of financial discourse - age appears not weary to them, nor the years condemn.