Speeches by UK prime ministers were rarely market moving events, despite what some of the more breathless commentators in the broadcast media would have you think. But perhaps this has changed since the Brexit referendum in June last year, even if the spin doctors manage the message in advance.

The main thrust of Theresa May’s speech this week was leaked in the days leading up to her address, so traders and investors were not exactly hanging on her every word. But there were still some pronouncements that did affect sentiment, particularly in the FX markets, such as the confirmation that the final deal will be put to parliament...