Reuben is a UK-based investor who shares interests in technology, real estate and hospitality with his billionaire brother, Simon. The siblings previously owned Global Switch, operator of data centers in Asia and Europe. They have prime real estate worldwide, including a London mansion that they bought for more than $200 million.
The majority of Reuben's fortune is derived from the sale of investments including data center operator Global Switch. Proceeds are adjusted to reflect taxes, market performance and the cost of purchases. Spokesman Charles Stewart-Smith confirmed Simon and David share the businesses equally.
They also have a global real estate portfolio spanning retail, leisure and office properties. These holdings include New York's 609 Fifth Avenue, more than 1,500 hectares (3,706.6 acres) of land across Spain's Balearic Islands and London's "In and Out Club," which they bought for at least $200 million in 2011. The total value of those holdings is based on available property purchase records as well as market pricing from property brokers including Savills and Colliers International and data provider RCA.
The brothers hold a range of other closely held investments spanning transportation, mining and technology firms. These are valued using reported acquisition costs, valuations of comparable peers or book value and included in cash and other assets.
Personal assets, such as art and private residences, are valued based on acquisition cost, according to a person familiar with the matter, who asked not to be identified as the details aren't public.
The Reuben family hold a 15% stake in Newcastle United Football Club, based on a July 2024 news release. It's valued using reported financial results and the average enterprise value-to-sales multiple of four publicly traded peers: Manchester United Plc, Juventus Football Club SpA, AFC Ajax NV and Borussia Dortmund GmbH & Co KGaA.
Stewart-Smith, the spokesman for the Reuben family, declined to comment on the valuation in November 2025.
David Reuben was born in Mumbai, then called Bombay, in 1938, three years before his younger brother, Simon. The sons of Jewish parents from Iraq, the pair moved to London as teenagers. David became a scrap metal dealer and began trading metal in the Soviet Union with Merrill Lynch in 1974. Three years later, he teamed up with Simon to create metals trader Trans-World Group.
They established a Russian office in 1991, and, with the help of partner Lev Chernoy, bought controlling stakes in Russian and Ukrainian aluminum plants. Five years later, they were the world's third-largest producer of the metal, with sales reaching $6 billion in 1997. The company was criticized by Russia's politicians and media, who attacked Trans-World's profit margins.
Faced with fines from Moscow and disgruntled ex-managers who were maneuvering to take control of their smelters, the brothers sold their interest in the company in 2000 for $250 million to billionaire Oleg Deripaska, and invested the proceeds in real estate, leisure interests and technology companies.
Reuben lives in London with his wife. The couple have a son, Jamie.