Nigerian billionaire Aliko Dangote, Africa’s richest person, fell 25 places on the Bloomberg Billionaires Index on Monday as the naira tumbled on its first day of trading without a peg to the U.S. dollar.

Dangote’s fortune fell $3.7 billion, knocking him to No. 71 on the Bloomberg ranking, down from No. 46 on Friday. The majority of Dangote’s $12.7 billion fortune is derived from a 91 percent stake in Dangote Cement Plc, which shed 2 percent in trading Monday.
The Central Bank of Nigeria began auctioning dollars to limit the currency’s decline. The bank had been using capital controls to stem an outflow of dollars after the naira crashed in February 2015 when oil prices slumped