James Gorman has said the word(s). Morgan Stanley will need to have a new hub inside the European Union. Morgan Stanley employees and their families who are currently based in London will need to move.
Good luck with that.
For an indication of how hard it is to prise entrenched staff and their spouses and their offspring out of London in the intention of happily resettling them elsewhere, Gorman need only look at the sorry tale of Jose Mourinho, the Manchester United manager.
Like many a London-based Morgan Stanley banker, Mourinho isn't British (he's Portuguese). Like many a London-based Morgan Stanley banker, he's spent a lot of time in the UK: first between 2004 and 2008 and then again from 2013. And like many a senior Morgan Stanley banker, Mourinho has children (17 and 20) who've grown up in London and don't want to go elsewhere.
As a result, he finds himself living alone in a hotel room eating takeaway meals while his wife and children continue living in London. And Mourinho isn't even in a distant EU outpost: he's in Manchester.
"My daughter will be 20 next week. My son will be 17 in a couple of months. They are very stable... university in London, football in London, friends," Mourinho told Sky Sports. "They are at an age where they can't chase me like they did before. So, for the first time, the family lives in a different way..."
Mourinho's says his hotel life is, "terrible." Ultimately he thinks he might buy a flat in Manchester. Even this won't be ideal: he'll still be away from his family and, "can't cook."
Gorman - and other senior bankers in London - should take note. As well as increasing costs for banks, Brexit could impose an emotional cost on bankers who relocate but whose families stay behind.
The only upside for euro-earning bankers is that London mortgages and school fees will become cheaper as sterling falls. The City could yet thrive as a lifestyle location. The work will take place in Dublin or Frankfurt.