The Brazilian Central Bank bought dollars in the futures market for the first time in 10 years, taking advantage of the real’s rally to reduce the stock of derivatives used to prevent excessive movements of the currency.

The central bank held an auction of so-called reverse swaps Wednesday, equivalent to a purchase of $500 million in the futures market. Analysts say the monetary authority will likely intervene in the same way again as high interest rates and diversification away from US assets fuels gains in emerging currencies including the real, which is up some 11% this year.