The Tech London Advocates research confirms what we already knew - that London's tech ecosystem is highly dependent on talent born overseas and so it is a natural fear that Brexit will have an impact on the ecosystem, and that uncertainty of where Brexit will land creates uncertainty in some investors minds.  TLA together with other groups are working hard to shape Brexit for the sector in a post Article 50 world but there is also a need to double up on efforts to differentiate the UK, retaining it's position as a market leader in Fintech, Cyber etc, self-insulating the sector from whatever shape of Brexit we end up with.