South Africa’s rand is on a weekly winning run not seen in more than two decades as elevated precious-metal prices and an improving economic backdrop drive gains.

The currency is on track for its eighth straight weekly advance against the dollar, which would be the longest streak since December 2002, according to data compiled by Bloomberg. It’s strengthened 6.1% over the period.

While record gold and silver prices have supported rand gains, economic reforms and a cautious central bank have also helped. Policy makers adopted a lower inflation target last year, boosting confidence that the country will maintain its interest-rate advantage over the US.

“Possibly, the main cyclical factor is the commodity tailwind,”, said Burak Baskurt, chief emerging markets strategist at BNP Paribas. “But structural factors mostly explain the sharp appreciation.”

Data next week may confirm that inflation has peaked, according to Bloomberg Economics. With the policy rate at 6.75% and annual inflation seen at about 3.6%, South Africa’s real interest rate is above 3%, offering an attractive real return.

“We see further gains for the rand and expect rates and bonds to rally further due to low inflation,” Societe Generale strategists including Phoenix Kalen and Marek Drimal wrote in a note Friday.

The gains extended beyond the currency. South Africa’s benchmark equity index has risen over 2% this week, hitting a record high as mining shares rallied.