Robert Defares: The Quiet Billionaire

The Quiet Billionaire with Surinamese Roots Who Invests His Wealth in Society

Robert “Rob” Defares, born in 1961, is one of the Netherlands’ most successful entrepreneurs with Surinamese roots. As the co-founder of IMC Financial Markets, he built an international trading powerhouse and accumulated a multibillion-euro fortune. Yet his significance cannot be measured by financial performance alone. Behind the extremely publicity-shy businessman is an influential patron who invests substantial amounts in education, cancer research, art, culture and social opportunity.

With the future Hartwig Museum, Defares is also giving his philanthropic legacy a permanent home in Amsterdam.

Surinamese Roots and a Name with History

Although Rob Defares was born in the Netherlands and his personal background is rarely discussed in detail because of his strong desire for privacy, he has Surinamese roots. Publications have described him as a prominent Dutch entrepreneur of Surinamese descent.

His family name is also historically connected to Suriname. The surname Defares was officially registered during the Emancipation of 1863 for formerly enslaved people on the De Drie Gebroeders plantation along the Suriname River. It remains a relatively rare surname worldwide, with its historical centre in Suriname.

Because Defares deliberately keeps his family history and private life away from public attention, further genealogical details have not been widely documented. The historical origin of his surname nevertheless represents a meaningful connection to Surinamese history.

This is precisely why his story belongs on SurinamStars—not only because of his exceptional commercial success, but also because his social work demonstrates how entrepreneurship, heritage and responsibility can reinforce one another.

From Amsterdam’s Trading Floor to the Global Stage

Defares’ business story began in 1989 on the trading floor of the Amsterdam Options Exchange. Together with René Schelvis, he founded International Marketmakers Combination, which later became known as IMC Financial Markets.

IMC was among the first trading firms to recognize the potential of automation and electronic trading. While traders had traditionally communicated orders through hand signals and loud calls, IMC developed automated systems capable of executing transactions faster and on a much larger scale.

The company grew into an international technology-driven trading firm operating across multiple financial markets and global trading hubs. Research, mathematical modelling, software engineering and high-speed infrastructure are now at the heart of its operations.

Defares led IMC for many years and remained closely connected to the company as a major shareholder after stepping away from its daily management. His success made him a permanent fixture near the top of the Quote 500 ranking of the wealthiest Dutch citizens.

Public estimates of his wealth change from year to year. In 2023, NOS reported, based on the Quote 500, that his fortune was estimated at €3.3 billion, placing him seventh among the wealthiest people in the Netherlands. Later estimates have been even higher. Defares has consequently been described for years as Amsterdam’s wealthiest resident and one of the richest entrepreneurs in the country.

What makes his story truly remarkable, however, is what he chooses to do with that wealth.

Capital as a Force for Social Progress

Defares rarely steps into the spotlight. Interviews are scarce, and he largely keeps his private life away from public attention. His social influence, by contrast, can be seen in many areas.

Through several foundations, he supports initiatives related to equal opportunity, poverty reduction, participation in sports, nature conservation, press freedom, medical science and culture. His approach to philanthropy appears to focus less on personal recognition and more on strengthening institutions capable of creating lasting change.

His social commitment addresses an issue that is particularly relevant in major cities: how can society prevent a child’s heritage, neighbourhood or family network from determining the opportunities available to them?

IMC Weekend School: Helping Young People Discover What Is Possible

In October 1997, Defares and IMC financed the establishment of IMC Weekend School. The initiative serves young people from communities where access to inspiring role models, professional networks and supplementary education cannot always be taken for granted.

Through the programme, students from different cultural backgrounds are introduced to a wide range of professional fields and meet experts who show them what opportunities exist in society and the labour market. Its guiding principle is that children must first be able to discover what is possible before they can make informed choices about their future.

Defares has remained closely involved in the development and professionalization of the organization from the very beginning. In November 2024, he transferred the chairmanship and became vice-chair of its Supervisory Board. The Weekend School is therefore much more than a charitable project. It is an investment in confidence, knowledge, social mobility and future generations.

In addition to his commitment to education, Defares supports poverty reduction and equal opportunity in Amsterdam. When awarding him the Gold Medal, the City emphasized that his social involvement extends across numerous fields, including support for young people, participation in sport, culture, medical science, nature and press freedom.

Hartwig Medical Foundation: Using Data to Improve Patient Care

Defares has also played an important role in medical science. Together with medical oncologist and researcher Emile Voest, he founded Hartwig Medical Foundation.

The foundation uses large-scale DNA analysis and medical data to improve the understanding of cancer and enable treatments to be more precisely tailored to individual patients. Since 2015, it has systematically performed whole-genome DNA analyses for patients with cancer, linking genetic information to treatment and outcome data.

The resulting Hartwig Medical Database has become the world’s largest database containing complete genetic and clinical data from patients with metastatic cancer. Its information supports scientific research and the continued development of precision medicine.

Defares did more than provide financial support. He helped create the conditions that allowed researchers to turn ambitious ideas into a professional and scalable programme. In doing so, he connected entrepreneurship to one of today’s most urgent medical questions: how can every patient receive the treatment best suited to the specific characteristics of their disease?

Art as a Public Legacy

Contemporary art forms another major part of Defares’ social commitment. He is internationally regarded as an influential collector, but his approach goes far beyond building a private collection.

Through Hartwig Art Foundation, he supports artists, new productions, exhibitions, educational programmes and collaborations with cultural institutions. The foundation commissions new work and acquires art that can help fill gaps in Dutch art history.

Remarkably, the foundation does not keep these works exclusively for itself. Its collection is donated to the Dutch National Collection, making the art available to museums and institutions in the Netherlands and abroad.

Within this philosophy, art is not the exclusive property of one collector. It is cultural heritage that should remain accessible to society.

Hartwig Museum: A New Home for Contemporary Art

Defares’ most visible cultural project will be Hartwig Museum in Amsterdam. The museum is being developed in the former courthouse on Parnassusweg in the city’s Zuidas district.

The partly listed Brutalist building, dating from 1975, is being renovated and extended. Its historic features will be preserved while a new section will provide space for exhibitions, studios, education, a library, an auditorium, music, hospitality and temporary accommodation for artists and other creators.

The museum is intended to be more than a place where art is displayed. It will also be an environment in which artists can live, work, conduct research, produce new work and exchange ideas. Young and emerging artists will be given space to develop their practice and present it to a broad audience.

Hartwig Museum is scheduled to open in 2028. Hartwig Art Foundation is financing the development from its own resources and is assuming much of the financial risk. The museum will not build a conventional closed collection of its own. Works arising from its activities may instead be acquired and donated to the Dutch National Collection.

Under the artistic leadership of Beatrix Ruf, Hartwig Museum aims to become an internationally significant centre for contemporary art and future artistic forms.

Amsterdam’s Highest Municipal Honour

On 12 March 2026, Mayor Femke Halsema presented Rob Defares with the City of Amsterdam’s Gold Medal. It is the city’s highest municipal honour and is awarded to individuals who have made an exceptional social, cultural or economic contribution to Amsterdam.

The city honoured Defares for his long-standing commitment to areas ranging from medical research and equal opportunity to poverty reduction, culture, sport, nature conservation and press freedom. For a man who rarely seeks publicity, the presentation marked an unusually public moment of recognition.

A Name Made Greater Through Giving

Rob Defares demonstrates that commercial success and social responsibility do not have to be opposites. He built a multibillion-euro company in a world driven by speed, data and split-second decisions. He then used a significant part of the opportunities created by that success to support education, science, art and the city of Amsterdam.

His story is therefore not simply about wealth. It is about what wealth can make possible.

His influence can be seen in young people from different cultural backgrounds discovering new ambitions through IMC Weekend School, researchers using genetic data to improve cancer treatment, artists receiving space to create ambitious new work and a monumental former courthouse being transformed into an international museum.

Defares deliberately keeps his family and private life away from the spotlight. His social legacy, however, is becoming increasingly visible.

The name Defares carries a historic Surinamese origin. In the present day, Rob Defares is giving that name a new dimension by connecting entrepreneurship with equal opportunity, scientific progress, art and social advancement.

With the planned opening of Hartwig Museum in 2028, that legacy will gain a permanent address, not as a monument to a single billionaire, but as a place where knowledge, imagination and new generations can come together.

Rob Defares prefers to let his capital speak quietly. Yet its impact is becoming louder every day.