Mariner has entered into an arrangement with State Street to use Charles River’s wealth platform as part of its longer-term growth strategy.

The decision comes as Mariner sets its sights on expanding its advisor team from the current 2,080 to 5,000.

Mariner CEO and president Marty Bicknell said: “This partnership reflects how we think about our company’s next chapter.

“It’s designed to support our journey to 5,000 advisors and beyond, while enabling a more unified and modern experience across the firm as it continues to grow.”

The firm is seeking to streamline daily operations for advisors and clients alike, laying down a centralised technology platform intended to handle expansion without increasing complexity or causing service disruption.

Charles River IMS is currently used by asset managers and related institutions in about 30 countries, supporting the management of assets worth roughly $59tn.

The software, integrated with State Street’s back-office functions, underpins the State Street Alpha platform.

Mariner’s adoption of the technology will focus on areas such as portfolio management, workflow automation for advisors, trade execution, custodial data integration, and enterprise-level data oversight.

State Street Wealth Services global head John Plansky said: “Mariner is a fast-growing firm in wealth management, and we’re thrilled to support them with a modern, centralised platform that strengthens the advisor experience.

“Charles River’s platform is built for firms operating at scale, helping them serve thousands of advisors through a single, flexible foundation designed to support disciplined and consistent growth.”

State Street, which owns Charles River Development, reported a net income of $747m in the fourth quarter of 2025, down 5% from $783m in the same quarter last year.

However, assets under management rose 20% over the year to reach $5.7tn at quarter’s end.