Oppenheimer family’s stock portfolio returns nearly 25% in 2025

Johannesburg – The public equity portfolio managed for South African billionaire Nicky Oppenheimer’s family and other relatives returned nearly 25% in US dollar terms in 2025, as investments across global markets delivered gains, according to the latest accounts of London-based investment firm Stockdale Street Ltd.

In a report published on October 18, Billionaires.Africa said equities were the best-performing asset class in the portfolio, while real estate and credit investments also recorded positive returns.

Stockdale Street said its venture capital portfolio “continues to grow and shows encouraging signs for the future”, adding that the funds it oversees mostly outperformed or matched their respective benchmarks.

The gains came despite a challenging global investment environment. According to Bloomberg, Oppenheimer’s wealth is derived largely from investments made with proceeds from the family’s sale of its remaining 40% stake in diamond producer De Beers to Anglo American in 2012 for $5.2 billion.

The family has since diversified beyond diamonds into private equity and businesses spanning consumer goods, manufacturing, healthcare and other sectors across Africa and Asia.

Broadly stable 

In a separate October 5 report, Billionaires.Africa detailed investments linked to the family, including Nigerian beverage-can manufacturer GZ Industries, South African promotional-products supplier Amrod and healthcare business Icon Oncology.

Stockdale Street’s financial results, however, showed that strong investment returns did not translate into higher profits for the firm. Its profit after tax fell 26% to £1.87 million ($2.48 million) in 2025, largely because of increased staffing and administrative costs associated with its US operations.

The firm’s fees remained broadly stable at £9.69 million ($12.8 million), compared with £9.76 million in 2024. It also paid £3 million in dividends to its two family shareholders, up from £2.5 million a year earlier.

Stockdale Street manages investments for two branches of the Oppenheimer family: Nicky Oppenheimer and his son Jonathan, and the family of his sister, Mary Slack. Each branch owns half of the firm, according to the report.

The latest performance highlights the family’s continued reliance on diversified investments following its exit from the diamond industry, although the reported portfolio return should not be confused with the overall growth in Oppenheimer’s personal wealth or the performance of every investment held by the family.