As news of Brexit broke, tech firms including BT, TalkTalk and software firm Sage reported share price falls.
For years, the UK - and particularly London - has championed the role of tech firms in buoying the economy.
Hundreds of start-ups have benefitted from the government's Tech City initiative, for example, and both employees and customers have been plucked from EU member states.
Much was once made of British companies' potential to compete with Silicon Valley - hence the nickname of the London hub of "Silicon Roundabout".
