Interest rates quoted in the markets are nominal, so one typically has to adjust them for inflation. Inflation determines the difference between nominal and real interest rates. Nominal interest rates are before taking inflation into account, while real rates are nominal rates adjusted for inflation. As there are several inflation indices (and many maturities), there are many measures of real interest rates. However, analysts often use yields on Treasury Inflation Protected Securities (TIPS), which are indexed to inflation (CPI) and their par value rises with inflation, as a proxy for real interest rates. Investors should remember that real interest rates are much more important for the gold market than changes in nominal interest rates, including the federal funds rate.