There is a wide variety of outcomes expected. The majority view in financial markets has been that the U.K. will stay in the EU, while many recent polls have shown those supporting leaving the trade bloc have taken a slight lead. That said, markets could still see a major shift in either direction when the results are released early Friday morning U.K. time.
Even with lots of pre-positioning, analysts say if the vote is to leave, the pound could fall further, stocks and commodities sell off and investors would seek safe havens like gold and bonds. A vote to stay may have the opposite effect, causing a snap back in the pound and risk assets and a sell-off in bonds.