Egypt’s richest man Nassef Sawiris experienced a sharp decline in his net worth just one week after surpassing the $290-million milestone in year-to-date wealth gains.

According to the Bloomberg Billionaires Index, which tracks the fortunes of the world’s 500 richest people, Sawiris’ net worth has decreased by $300 million over the past week.

The dip in his net worth has not only wiped out his earlier wealth gains for the year but has also brought his current net worth down to $7.02 billion, from $7.32 billion a week ago.

The $300-million slump in his net worth follows a noteworthy $294-million surge in his net worth from Jan. 1 to March 10 due to a sustained upsurge in the market value of his publicly traded assets in Europe.

Sawiris’ stakes in Adidas and OCI fall below $1.9 billion and $2.6 billion

Data tracked by Billionaires.Africa revealed that the decline in his wealth figures can be attributed to the performance of his six-percent stake in Adidas AG, a major global sportswear producer, and his 38-percent stake in OCI N.V., a Dutch-based top global distributor and producer of nitrogen and methanol products.

Over the past week, Adidas shares have declined by 4.89 percent, while OCI shares have lost approximately 4.2 percent of their market value.

These declines have resulted in the market value of Sawiris’ stakes in both companies falling below $1.9 billion ($1.87 billion) and $2.6 billion ($2.59 billion), respectively.

Recent loss widens wealth gap between Nassef Sawiris and Abdul Samad Rabiu

Following the sharp $300 million slump in Sawiris’ net worth in the past seven days, his year-to-date wealth gains of $294 million between Jan. 1 and March 10 have now turned into a year-to-date loss of $4.87 million.

This has resulted in a more significant wealth gap between Sawiris and Abdul Samad Rabiu, the Nigerian cement magnate who overtook him as Africa’s fourth-richest person.

Presently, Rabiu’s net worth stands at $7.7 billion, thanks to his stakes in publicly listed BUA Cement and BUA Foods. Rabiu is the founder of BUA Group, a rapidly expanding manufacturing conglomerate in Africa.