Nucleus director Bruce Wilson has stepped down from the board.
Wilson has been a director since the platform launched and has been non-executive director since 2011.
He is also a non-executive director at Helm Godfrey, a shareholder in the Edinburgh-based platform.
Nucleus says a replacement will be confirmed “in due course”.
Nucleus chief executive David Ferguson says: ”I can confirm that Bruce is retiring from the Nucleus board. He has been a fantastic ambassador for Nucleus since the very beginning and we appreciate everything he has done for the business and its member firms.
“On a personal level, I have learnt a great deal from Bruce – we all wish him the very best for the future.”
Accounts published in April show the platform made a profit of £1.4m in 2013.