His departure follows the £145 million takeover by James Hay Holdings earlier this year, leading to the capital firm disappearing from the stock market.
Ferguson is to step down from the board and leave following a period of handover, the group has confirmed. Meanwhile, the Nucleus name is to be used for the enlarged group, replacing James Hay's name and brand.
Chief executive Ferguson set up the Nucleus business with the backing of a number of financial advice firms in 2006, though its roots stretch back further. It has developed software platforms that enable financial advisers to provide online access to clients for investments across ISAs, pensions and bond accounts.
The “wrap platform” provider, which floated in 2018, is seen as one of the biggest successes of Scotland’s burgeoning fintech – financial technology – sector.
In a strategic update, Nucleus said: “While the Nucleus and James Hay platforms will continue to operate separately for the immediate future, and there is no current change to the operations or services of either, the strategic review will help to inform the creation of a leading financial planning and retirement-focused adviser platform, developed from the best features of both existing platforms.”
Having joined the board of Nucleus earlier this month, Richard Rowney, group chief executive of James Hay, will now assume day-to-day responsibility for the leadership of the enlarged group.
He said: "Today's announcement is a significant milestone, enabling us to harness what is best from both businesses, on behalf of our customers.
“I would like to reiterate our great respect and admiration for what David Ferguson has achieved as a founder of Nucleus, and on behalf of everyone I would like to wish him all the very best for the future."
Ferguson said: “With the company now becoming a key part of a much bigger picture with James Hay, it feels like the right time for me to move on and consider a new challenge. I hand over to Richard and wish him, his leadership team and all my colleagues, new and old, best wishes for the future."