A month ago it was a 14.6% chance
I’ve been on the Yes side of this bet for a week or so simply because I believe that TMay is so damn stubborn and focussed. Note the precise terms of this bet.
“For the purposes of this market leaving the EU is defined as the date when the treaties of the EU cease to apply to the UK. Examples of when this might occur include, but are not limited, to: the date specified in a withdrawal agreement between the UK and the EU; the end of the two year negotiating period (29/03/2019) as set out by Article 50 of the Lisbon Treaty (or any extension to this time period); or the date of the repeal of the 1972 European Communities Act. If more than one of these events were to occur, this market will be settled on the first of these events to occur. In the case of the two year time period in Article 50 being extended, via a unanimous vote by all EU Member States, we will settle this market on the extended date. This market will settle when the UK leaves the EU even if parts of the UK (e.g. Scotland, Northern Ireland) leave the UK or receive special status within the EU.