PA have “fact checked” BoJo’s claim this afternoon that “the pound soared” as a result of the Lancaster House speech:

DID POUND 'SOAR' AFTER MAY'S LANCASTER HOUSE SPEECH 
AS BORIS JOHNSON TOLD MPS?

PA
POLITICS Brexit Pound
18-Jul-2018 16:16:35
By Ian Jones, Press Association

Boris Johnson told the House of Commons "the pound soared" following 
Theresa May's Lancaster House speech - but 24 hours after the 
prime minister's statement, sterling had lost value against the dollar.

On the day of the speech, January 17 2017, the pound traded 
at 1.24 US dollars.

The following day it had slipped to 1.23 US dollars.

Look at the chart above, the £ started the day at $1.20. During and in the immediate aftermath of the speech the £ did indeed soar. Closing the London trading day at the $1.24 high. This is a significant move in currency markets. Boris was absolutely correct.

Overnight profit taking does not invalidate his assertion and the £ continued to rise in the following weeks. PA is being less than objective in framing the move as they did.