Rokstone strengthens leadership with key appointments
- September 12, 2025
- Posted by: Beth Musselwhite
- Category: Insurance
Rokstone, a speciality re/insurance MGA and part of Aventum Group, has announced the appointments of Stuart Lee as Chief Actuary and Martin Thomas as Head of Underwriting Management.
These appointments are expected to enhance decision-making and operational excellence across the business.
In his new role, Lee will lead and build Rokstone’s dedicated in-house reserving and pricing functions with technical rigour.
He joins Rokstone from Markel, where he worked for nearly 14 years, most recently as Chief Actuary.
Previously, he served as an Actuarial Analyst at KPMG for five years and as an Economic Analyst at the Bank of England for a year.
Commenting on his new role, Lee stated, “I’m delighted to join Rokstone. It’s different – it has a great culture, a place with no elitism or ego and an ‘all for one, one for all’ culture. Its portfolio is broad and diverse, which is a challenge I relish and they value talent and expertise; Rokstone has solid foundations for the team to build on, but I know I can make a difference here with my experience and that’s rewarding. It also has a highly collaborative approach and a refreshing desire to make the actuarial team part of front office decision making. I’m excited to be building out Rokstone’s actuarial capabilities to ensure we continue to deliver superior outcomes for carriers as we grow.”
As Rokstone’s new Head of Underwriting Management, Thomas will oversee underwriting management, operational control, governance frameworks, risk monitoring and control, regulatory governance, internal and external audit, underwriting authorities, policies and licensing, and business change management.
Thomas joins from Probitas, where he was Head of Underwriting Management for over three years.
Prior to that, he held various leadership roles at StarStone Insurance for over five years, most recently as Deputy Active Underwriter, Syndicate 1301. He also worked as a Marketing Executive at Willis for a year and as Business Development & Marketing Manager at Occam Underwriting for three years.
Sharing his excitement for his new role, Thomas said, “I’m excited to be part of the Rokstone team. It’s a unique business, and it needs a unique underwriting framework to match. I am working from a foundation of excellence, but as a problem solver and solution designer I know there is always a better way of doing things – something Rokstone lives by too.”
Ian Anson, Managing Director at Rokstone, expressed enthusiasm for the appointments of Lee and Thomas, stating, “Stuart brings an incredible depth of expertise and technical rigour to lead and build our internal reserving and pricing functions within Rokstone. Likewise, Martin has an impressive background in underwriting management and will play a crucial role ensuring we continue to deliver exceptional service to our clients and markets.”
“Our mantra is that of a virtual insurer with the fully developed infrastructure of a balance sheet insurer. We’re dedicated to protecting the capital of our partner insurers, treating carriers’ outcomes like they’re our own and these senior appointments are evidence of our commitment in this regard. Both of these functions will ensure Rokstone remains the most robust of underwriting agencies for carriers to entrust their capital to and furthers our aim to become the most inspirational (re)insurance MGA in the world,” Anson concluded.
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