There are too many examples in political betting when favourites have not won to make the assertion that betting can be predictive. What historical trends do show, as in the above betdata.io chart, is how those ready to risk their cash on the Betfair exchange are seeing things at a given moment.
As is reflected above over the past six months there have been periods when the money has been going on a UK exit happening first and when a general election is seen as more likely to take place.
At the moment the 74% favourite is that we’ll see an election first. That seems to take the view that there will be no crashing out of the EU without a deal at the end of the month.
The real challenge at the moment is that the executive cannot command a majority in parliament and there is always the possibility that the majority of MPs in the Commons will take control. Perhaps the only way of resolving this is through a general election something that Corbyn and not Johnson are now able to determine.