Patrice Motsepe, Africa’s first black billionaire, has lost nearly one billion dollars from his fortune this year after a sharp sell-off in South African mining stocks eroded the value of his holdings in Harmony Gold and African Rainbow Minerals (ARM).

The South African mining magnate and president of the Confederation of African Football (CAF) has seen his estimated net worth fall from $4.3 billion at the beginning of March to $3.4 billion as of July 30, according to Forbes, wiping $900 million off his wealth in five months.

The decline has also reshuffled the rich list in Africa’s largest economy. After rising to become the country’s third-richest person earlier this year, Motsepe now ranks fifth, behind Michiel Le Roux and Koos Bekker.

Most of Motsepe’s wealth is tied to his mining investments. He owns an indirect 11.8 percent stake in Harmony Gold, South Africa’s largest gold producer, through a holding dating back to Harmony’s merger with Avmin in 2003. He is also the controlling shareholder of ARM, one of the country’s largest diversified mining companies.

Both stocks have come under heavy pressure over the past six months despite strong commodity markets.