Here is the real problem for Brexit, from Goldman:
Following the Brexit surprise, we revised our Sterling forecasts weaker, but – amid lots of doomsday scenarios for the Pound – resisted the temptation to forecast a free-fall. Now that markets have settled somewhat,we are switching to forecast a second leg of weakness for the Pound, as the Bank of England’s policy response drives the currency weaker.
…The market is not discounting the easing effect of asset purchases, the persistence of easier monetary conditions in the UK, and the US-UK monetary policy divergence that we expect nearly as much as it should.