About us

Investment team

David Tyerman

Managing Director, Investment Manager

T: 01243 753 415

David has a degree in Biochemistry from Cardiff University and a post-graduate qualification from City University Business School. He began his City career at Societe Generale before taking up a role managing the portfolios of ultra-high net worth investors. David specialises in advising high net worth families, estates and institutions heading the Private Office services of Thesis.

Tony Gammon, Chartered FCSI


T: 01273 322 436

Tony trained with Barclays Bank before joining Thesis in 1980. His wide experience of portfolio management is especially focused on his interest in Trusts and charity clients. He runs the Brighton office and is our Client Services Director.He also is a member of the Asset Allocation committee and Chairs the Fixed Interest Committee. Investment experience since 1978.

Giles Marriage, Chartered FCSI


T: 01590 613 583

Giles graduated in Psychology before beginning his career with Cazenove Fund Management where he specialised in Emerging Markets. He has wide experience of portfolio management, and prior to joining Thesis, Giles was advising a high net worth family Trust. Giles runs the Lymington office and also advises institutions on asset allocation and investment selection. Investment experience since 1994.

James Nield ASIP, Chartered FCSI

Office Director, Investment Manager

T: 01243 521 784

James began his career at Cazenove Fund Management, where he spent five years as assistant manager of a Global Emerging Markets Fund. He spent the next 11 years specialising in UK equities at Oriel Securities, where he was a partner, and at Royal Bank of Canada. He also runs the Chichester office private client team. Investment Experience since 1997.

Jeremy (Jem) TurrellJem Turrell, Chartered MCSI

Office Director, Investment Manager

T: 01483 406 104

Jem has over 25 years’ experience in the financial services industry, extensively advising high net worth individuals and helping families achieve their financial goals and objectives. His primary aim is to build client-centric and holistic relationships to deliver financial peace of mind. He is a Chartered Member of the Chartered Institute of Securities and Investments, a Member of the Personal Finance Society, as well as the Chartered Insurance Institute. Outside of work he volunteers as a Treasurer for a charity.

Steven Richards, Chartered FCSI

Associate Director, Fund Manager

T: 01483 406 108

Steven spent many years as a Private Client Manager but the last five years managing Thesis’ Optima Portfolio Service and Balanced and Growth Funds. He heads Thesis’ Pooled Vehicles Selection Committee as well as sitting on Asset Allocation. Steve also works on a number of Private Office Funds and Group Pension mandates, and as an Associate Director is involved with Strategic business management issues. Investment experience since 1993.

Adam Burniston

Model Portfolio Manager

T: 01483 406 107

Adam is in his fifth year at Thesis and is the company’s Model Portfolio Manager. Along with Steven, he is responsible for the Thesis Model Portfolio Service as well as a number of partner investment processes. He has expertise in fund selection having being a Fund & Research Analyst in his previous role. Adam holds the Investment Management Certificate (IMC) and is currently working towards completion of the Chartered Financial Analyst (CFA) course.

Robert Clough CFA, Chartered FCSI

Investment Manager

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Robert read Biochemistry at Edinburgh University then worked at HSBC for eight years managing private client and charity portfolios. He subsequently moved to Asset Value Investors and joined the Chichester office as an investment manager from Canaccord Genuity where he was responsible for researching and analysing investments and managing client portfolios. Robert has 14 years multi-asset investment experience, is a Chartered Fellow of the Chartered Institute for Securities & Investment and is a CFA Charterholder.

Alice Farrer, MCSI

Investment Manager

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After graduating in Economics with French from Durham University, Alice joined the Charity Investment Team at HSBC Private Bank in London where she worked for six years assisting in the management of charity and private client investments. Following a sabbatical in Ghana working with young people to create positive change, she followed her passion for philanthropy working at London law firm, Slaughter and May, within their Charitable Partnerships team. She then spent six years managing charity and private client portfolios at EFG Harris Allday, a leading Midlands Stockbroker, before moving to West Sussex with her family and joining Thesis in January 2018.

Tim HarmanTim Harman

Investment Manager

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Tim studied Economic and Political Development at Exeter University before beginning his career in finance at PwC. He is based in the Guildford office and manages private client, trust and charity portfolios. Tim has 15 years’ financial markets experience, specialising in North American equities at BMO Financial Group and at the Royal Bank of Canada, where he was responsible for the firm’s Canadian Equities business in Europe and sat on the European Equities Operating Committee. Tim is a Member of the Chartered Institute for Securities and Investment.

Michael Johnstone, Chartered MCSI

Head of Charities

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Michael’s career began over 42 years ago when he joined the London Stock Exchange as a trainee jobber on the market floor. He spent 5 years in Wall Street returning to London in 1984 to open trading desks in European shares and ADRs for W Greenwell. He also worked at BZW and SGST Securities before  founding  his own stockbroking business, Burrough Johnstone,  in 1991, and moved his private client business to Thesis in 2015 where he is Head of Charities. Michael works with high net worth families.

Paul Morley, Chartered FCSI

Investment Manager

T: 01273 322 435

After graduating from the University of East Anglia in 2003, Paul worked for the Bank of Ireland in Dublin before joining the Thesis Brighton team in 2007. He is a Chartered Fellow of the Chartered Institute of Securities and Investments, having achieved the CISI Masters in Wealth Management and the CFA Investment Management Certificate. He also holds the designation of Chartered Wealth Manager. Paul concentrates on managing investment portfolios for private individuals, trusts and charities.

Jonathan R Yousafzai, Chartered FCSI

Investment Manager

T: 01590 613 585

Jonathan read Chemistry at Oxford and after brief spells at ICI and Chase Manhattan, moved into fund management at Abbey Life Investment Services. At Abbey Life, Jonathan managed a wide variety of UK institutional funds, including its flagship Ethical Unit Trust. In 1998 Jonathan moved to Lymington to dedicate himself to discretionary investment management. Investment experience since 1987.

Joe Boxall, Chartered MCSI

Assistant Investment Manager

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Joe joined Thesis in January 2014 after completing his bachelor degree in Mathematics at the University of Southampton. Having joined as a Portfolio Assistant, Joe is now an Assistant Investment Manager who provides support to the Investment Managers in the office. Joe is a Chartered member of the Chartered Institute of Securities and Investments, having achieved the CFA UK Level 4 Certificate in Investment Management and also having passed CFA Levels 1 and 2.

Dan Thompson

Assistant Model Portfolio Manager

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Dan joined Thesis in 2016 after graduating with an Economics Degree from Cardiff University. He holds the Investment Management Certificate (IMC) and is currently studying for his CFA qualification. He works with the Model Portfolio team being involved in investment committees, supporting adviser propositions by producing market commentary and performance attribution.

Emma Wright

Assistant Investment Manager

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Emma graduated from the University of Surrey in 2017 with a degree in Economics in Finance. She joined Thesis as an Investment Assistant following university and quickly progressed within her role resulting in her promotion to Assistant Investment Manager. In her spare time, she enjoys socialising with friends, playing the piano, and going for beach walks in her home town of Poole.

Harry Henshaw

Investment Assistant

T: 01243 521 790

Harry joined Thesis as an Investment Assistant in February 2017 having graduated from Cardiff University with a degree in Music. He works in the Chichester Office, where he provides support to the Investment Managers. While at Thesis Harry has achieved the CFA UK Level 4 Certificate in Investment Management and is currently working towards achieving Chartered Wealth Manager status with the Chartered Institute of Securities and Investments. In his spare time, Harry continues to enjoy playing music, as well as playing squash for Chichester.

Jo Jedracha

Investment Assistant

T: 01273 322 433

Jo started her financial career in 2000 working for Santander while studying towards a degree in Business at University. She joined Thesis in 2008 as a Portfolio Assistant in the Brighton Office, before gaining a promotion to Investment Assistant. Her main duties involve assisting both managers and clients providing administrative support to the team.

Julia Taltavull

Investment Assistant

T: 01483 406 117

Julia studied Administration and Finance in Barcelona prior to moving to the UK. She started her working life in Bath where she focused on office management. She then moved to Guildford in 2017, joining Thesis as an Investment Assistant, where she is currently studying towards her Investment Management Certificate. In her spare time, Julia enjoys visiting her family and friends in her home of Menorca, playing tennis, and takes an interest in fashion.