The great bubble hunt is on. As the tenth anniversary of the Lehman collapse approaches, sleuths are scouring the financial landscape for signs of ballooning markets that could burst with similar disastrous consequences. Of the possible candidates there is one clear favourite: leveraged loans.

Look, warn the doomsayers, the same thing is happening again. The same banks are piling mountains of debt onto over-borrowed companies then selling it on to complex securitisation vehicles. Have they learned nothing?