Lowcock joined Bestinvest in October 2003 as a senior investment adviser and now heads up a team of advisers.
He is to join Hargreaves Lansdown in November as an investment manager in the research team and will be working primarily in PR and research functions around funds.
Danny Cox, head of advice at Hargreaves Lansdown, said Lowcock was not replacing anyone, although earlier this year Ben Yearsley left his role as investment manager at the firm after a 14-year stint there.
“We are always looking for high quality people to join the team and build the business,” Cox said, “It is not any sort of specific expansion and he is not replacing anyone.”