We're stopping taking new bets on the "Brexit - Will the UK leave the EU before 2019 ends?" bet tomorrow as things look they could be decided at any moment. So get your bets in while you still can.
I just made my bet on this event before it's too late. I personally don't think that UK should leave the EU. And not because I think the EU is perfect as it is right now, but rather because I think that countries such as France, Germany, Denmark, Netherlands and some other typically Western ones should better stay together than be divided. If anything, there are countries in the EU currently which wouldn't be missed much if they left the Union. But this is definitely not the case with the UK. With all that in mind I bet on YES, because this is what will happen in the nearest future imo.
With Boris Johnson as their leader they are definitly going to leave the EU, Johnson is one of the Brexit-hardliners if not THE hardliner. Tides may change when the rumours of re elections are true and a Brexit opponent wins the election. At the current state I would definitly bet "Yes", too.