There are approximately 80,000 banking jobs in London....which relate to the Euro and derivatives sold. There's some discussion now that those 80,000 jobs may be lost (maybe not in 2017 or 2018....but eventually by 2019 when BREXIT is finalized).
The general affect on London?
It's a city of 8.7 million people....so 80,000 might not be a big deal, but there are implications.
First, these were 80,000 high-end jobs which paid well. These were the people who owned half-million-pound condos and houses. These were the people who spent a fair amount on booze and drinks after work to discuss deals. These were the people who shopped at fine clothing shops and spent lots of bonus money on fancy suits. These were people who spent a fair amount of money on gifts for their wife or husband. These were people who booked big weekend trips to Oslo, Paris, or Rome.
That money won't flow through London, and it'll have a harsh affect on dozens of different business fronts around London. There are pubs which likely spent decades greeting these individuals after work, and there's virtually no replacement customers existing.
Second, the high-end homes and apartments? You will see a major hit on pricing, and a sudden availability of thousands of places.....with a very limited number of people willing to pay the asking prices.
Third, as these people go.....their families, their liaison-mistress, and their support people within the banking structure will likely also move. So in total....it might be near 200,000 people end up leaving London.....if you count the kids as well.
Fourth, those students in the British schooling system....set to graduate in two years or more? They will all be applying their resumes toward international situations outside of England. You could looking at an entire class of 300 business-degree students....all working outside of the UK upon graduation.
The big-wigs of London? I suspect they are all having panic-attacks and fits of anger over this whole BREXIT thing. The taxes upon the 80,000 and their banking sector in London....meant a lot in terms of tax revenue. Now? It's a problem.....less revenue....less taxation....less 'gift' money.
Long term, it's a big problem.