LTPZ offers exposure by tracking an index of US TIPS or Treasury inflation-protected securities with $1 billion in outstanding face value and have at least 15 years remaining to maturity. TIPS provide returns that are linked to the monthly change in inflation, as measured by the Consumer Price Index. As TIPS mature, the adjusted or original principal are paid, whichever amount is greater. The fund uses a sampling method in tracking the index, which means it will invest in a sample of securities that collectively have an investment profile similar to that of the underlying index. The index is rebalanced monthly.