USD/SAR is an exchange rate that specifies how much SAR (Saudi riyal) can be converted into one USD (US Dollar). Therefore, the base currency is USD, and the price currency is SAR. When that trend decreases, that means that SAR appreciates compared to the USD. If this pace rises that implies that SAR depreciates against the USD. There are several macroeconomic factors (fundamentals) impacting the exchange rate of USD/SAR. GDP, interest rates, Consumer Price Index (CPI) or inflation, and other monetary policies introduced by central banks are the most prominent factors.