Simon is the grandson of Ramsey Crookall's founder. He studied Economics at Durham University and then joined the graduate program at the high-yield bond market specialist Hambros Bank, trading for them in Sydney and Asia during the 1990s. He then worked for CIBC Global Markets in London before becoming a successful entrepreneur.

Simon co-founded Gumtree, Slando and InvestEngine. He joined Ramsey Crookall in 2012 and currently sits on their board and investment committee.