While there are plenty of forecasts of what damage Brexit will do to London business, the truth is that this is yet to be demonstrated in any meaningful way.
Is it because of the sheer scope of London and its business sector? That has to be a real question as you look at the willingness of large international companies to take space in Kings Cross; Chinese and other foreign developers and investors to buy and build; tech companies to expand in Shoreditch and Aldgate; the South Bank to grow and the City of London to build skyscrapers.
Of course, there is caution until the way ahead becomes clear (after negotiations with the EU) but a guess might be that the sheer scale of the expansion in London (particularly with new transport links such as Cross rail and Thameslink) puts it in a strong position.
That does not mean that there will not be some slowing, which seems inevitable in the circumstances. In any case the market anticipates that the current cycle will come to an end in the next 18 months.