Treasury Inflation-Protected Securities (TIPS) are five, 10 and 30-year securities sold by the US Treasury (a US government agency) that provide holders with a hedge against rising inflation. The future value of conventional US Treasuries is eroded by inflation. By contrast, the principal value of TIPS is adjusted every six months by the rate of consumer inflation (the CPI index). This means the principal value rises with inflation (although conversely it falls during periods of negative inflation). While the coupon on TIPS does not change, the amount of interest paid is based on the principal value, so if this accretes in line with inflation, coupon payments will reflect the higher principal value. TIPS holders are also protected against deflation as the principal value at maturity will be the higher of the accreted value or the original principal amount. As of November 2021, there were USD1.695 trillion in TIPS outstanding.