The premium to bet on the pound’s volatility in the next two weeks relative to one-month wagers has surged to the highest level since the aftermath of the Brexit vote ahead of next week’s U.K. snap election.

As Bloomberg notes, even though polls suggest Prime Minister Theresa May remains on track to increase her parliamentary majority...

But, so-called butterfly options...

Show the pound’s moves in the next two weeks could be the largest since the currency’s flash crash in October, when it dropped 6 percent in just one minute.