you mention facts with hyperbole and not looking at other information. £/$ dropped around 10-12% between Jun 2015 and Jun 2016, do you remember the impending doom that caused? did you notice it? combined, its 20-25% in 18months, not a great story but there are upsides (helps exports) and the underlying cause is low interest rates. Brexit is a short term catalyst for speculators and traders to abuse.
We had them before.
The underlying cause is negativity and uncertainty on the future of the economy after Brexit.