This year, TIP outperformed both the iShares Barclays 7-10 Year Treasury Bond Fund ( IEF ) and the iShares Barclays 10-20 Year Treasury Bond Fund ( TLH ) on a total return basis. Monetary inflation refers to the dilution of ancient coins' intrinsic value-back when gold and silver were the currency of the day-by the alloy of precious with base metals. This makes sense since the principal value of Treasury Inflation-Protected Securities adjust to accommodate changes in CPI-U, i.e., inflating apace with an upward CPI trend to protect the holder's purchasing power.