One of London's top quants has quit one of London's top hedge funds. : One of London's top quants is on the move. Vladimir Piterbarg, the former head of quantitative analytics at Barclays, who joined the Rokos family office in 2015, has left again according to insiders. His destination is unclear. Piterbarg didn't respond to a request to comment on his plans, but a Rokos employee confirmed his exit. Piterbarg is understood to have left around a month ago, despite still being registered as employed by Rokos on the London Financial Conduct Authority (FCA) Register.