This really is a difficult one to forecast because skills, reputation and reach of the London stock market for example is something only European counterparts can dream of. A no deal would seem to be the worst outcome for everybody?
The reality is that the EU has been trying to dilute the power of the London financial markets for many years now - pay back for the UK not adopting the Euro? While France and other EU members would like to increase the influence of their local financial servcies industries it is Germany which would benefit most from any demise in London markets - in my view.
The flap over Brexit will not last forever and I think there is a lot more pain coming towards the EU - the Germans are already complaining that they have become a cash cow and the situation will get worse after the UK leaves. However, now is not the time to buy London property as I think we will see a sudden and sharp sell-off at some point.