There is also TIPS (Treasury Inflation Protected Securities), also known as Inflation Linked fixed income. TIPS are sold by the US Treasury and have a "real yield". The bond or note's face value is adjusted upwards with the CPI-U, and a real yield is applied to the adjusted principal to let the investor always outperform the inflation rate and protect purchasing power. However, many economists believe that the CPI under-represents actual inflation. In the event of deflation over the life of this type of fixed income, TIPS still mature at the price at which they were sold (initial face). Losing money on TIPS if bought at the initial auction and held to maturity is not possible even if deflation was long lasting.