Victoria Hasler, head of research at Square Mile Investment Consulting & Research, has left the business after almost six years with the firm.
A spokesman for the business confirmed the departure, which he said was "amicable" and a "mutual decision".
The spokesman said: "I am sorry to confirm that Victoria has left Square Mile. This is an amicable and mutual decision.
"Victoria has been with the firm for nearly six years, essentially from when it was founded, and has made a very positive contribution through building up our research and consultancy business over this time. We would like to thank her for her contribution."
At Square Mile, Hasler led the firm's team of analysts and specialised in fixed income research, according to her Linkedin profile.
Previous roles included assistant director and fund analyst at Brewin Dolphin, fixed income and balanced portfolio manager at Rothschild Private Bank and investment analyst at Merrill Lynch Investment Managers.