A statement from a Fidelity spokesperson revealed that Mullan’s decision is entirely personal and that he is taking a break to travel.

“We have initiated a search for a successor. Jim Burton, currently chief marketing officer for personal investing at Fidelity Investments, will join in early March to manage the UK business while we undertake a detailed search for Hugh’s ultimate successor over the coming months,” the statement added.

Burton’s current responsibilities include Fidelity’s retail customer strategy, customer segment management, advertising, sales and service models, thought leadership publications, and retirement investing initiatives. He was also formerly president of Fidelity Brokerage Services, leading its trading and research capabilities for equities, derivatives and fixed income products.

Prior to joining Fidelity in 2007, Burton spent eight years with Charles Schwab in San Francisco where he was senior vice president of advised investing products. He previously served as a consultant with LEK Consulting in Europe and Australia, as well as with Arthur Andersen's consulting group.

Only last month, the firm also revealed that its head of asset management Ronald O’Hanley, would be stepping down after less than four years in the role. Read more on that story, here.