Gross Domestic Product (GDP) measures the total value of all goods and services produced by the economy. A rising trend has a positive effect on the nation's currency. GDP is the broadest measure of activity and the primary gauge of the economy's health. To foreign investors, a strong economy is viewed favorably because it spurs investment opportunities in the domestic stock and bond markets. More importantly, the central bank is more likely to raise interest rates in the face of a strong and growing economy. The combination of these effects can have a large impact on the demand for the nation's currency.