European banks also appear to have built up cash buffers in US dollars earlier in the year. Cash holdings of foreign banks in the United States, presumably a  BIS central bankers’ speeches  7  reasonable share of which are European, had risen to over $ trillion from less than $ billion earlier this year before declining (Graph 10).
If policymakers on both sides agree on one thing, it’s that arranging the divorce between the UK and the EU is going to be very hard. European Commission President Juncker expects the negotiations to be “very, very, very difficult", and UK’s Brexit Secretary Davis predicts they will become the "most complicated" negotiations of all time.