Inflation-Protected Bond

IntermediateBonds & Fixed Income2 min read

Quick Definition

A bond whose principal or coupon adjusts with inflation, preserving the investor's purchasing power regardless of price level changes.

What Is Inflation-Protected Bond?

Inflation-protected bonds are fixed-income securities designed to shield investors from inflation's erosion of purchasing power. The principal value of these bonds adjusts with an inflation index (typically CPI), and coupon payments are calculated on the adjusted principal, so both principal and interest grow with inflation. U.S. Treasury Inflation-Protected Securities (TIPS) are the most prominent example: a $1,000 TIPS with 2% coupon rate would have its principal adjusted to $1,030 after 3% inflation, and the coupon would be calculated on $1,030 (paying $20.60 instead of $20). At maturity, the holder receives the greater of the inflation-adjusted principal or the original face value, providing deflation protection as well. The "real yield" on TIPS represents the return above inflation. Other countries issue similar securities: UK index-linked gilts, Canadian Real Return Bonds, and French OATi. Inflation-protected bonds tend to underperform conventional bonds when actual inflation is lower than expected, and outperform when inflation exceeds expectations.

Inflation-Protected Bond Example

  • 1A 10-year TIPS with 1.5% real yield and 3% annual inflation delivers ~4.5% nominal return, automatically keeping pace with rising prices
  • 2During 2021-2022 inflation surge, TIPS outperformed nominal Treasuries by 10%+ as unexpected inflation boosted their principal adjustments