On 23 June 2016, there will be a referendum in the United Kingdom (UK) on the question of whether or not the country should remain in the European Union (EU). We use the polls as a measure of the likelihood of an exit to examine the likely effect of a Brexit on financial markets. “Whenever the probability in the polls of a Brexit moves above 50%, we observe a substantial depreciation of the UK pound with respect to most major currencies (including the euro), and strong decline in bank stock prices, suggesting that markets feel the financial sector (both in the UK and the EU) will be most severely affected by a Brexit”, IWH President Reint E. Gropp says. There is little effect on the euro/US Dollar exchange rate. “A huge concern is that overall market volatility both in the UK and the EU are on record highs since last Thursday, reflecting the higher uncertainty associated with Brexit and how exactly, if it happened, it would come about.” Within the UK, we see some evidence for a flight to safety into UK government bonds, but no effects for German bonds.