The multimillion-dollar drop in his net worth can be attributed to the performance of his 9.14-percent stake in Richemont.
Seacom is privately funded and 75 percent African-owned.
Rupert's investment firm, Remgro, owns 44.6 percent of Mediclinic, South Africa's largest hospital operator.
The majority of Rupert's fortune stems from his stake in Richemont.
This statement comes nearly a week after Richemont reported a double-digit increase in sales in Q1 2023.
The increase in Rupert's net worth follows a surge in Richemont shares from $10 on July 15 to $11 today.
Despite the strong performance, Richemont shares have fallen 5.7 percent since this morning.
Similarly, Remgro's 44.6-percent stake in Mediclinc has increased in value by $281.5 million.
The news comes nearly four weeks after Mediclinic rejected an acquisition bid from Rupert's Remgro.
Reinet Investments S.C.A. is a Luxembourg-based investment vehicle.
