Sterling is dropping because that's probably what the banking infrastructure, who effectively set the bounds with in which other players may trade, have decided will happen.

In reality there are so many different factors that affect the relative value of any currency or commodity that's it's impossible to pin down any one thing.

As a side note, I noticed a couple of people claiming the UK is doomed, we're finished etc etc.  I'm curious why those of you who think that right now seem to think that being part of the sinking ship that is the EU would help us.

Let's face it, the EU institution and it's insane currency are doomed.  That doesn't mean Europe is & out of the flames might emerge something that looks like the remains of a EU, a smaller council, and a number of overlapping trading blocks across Europe.

Don't let anyone tell you we won't be trading with our European friends.  We will continue to trade.