Inflation-linked government bond
Rules, protection and tax below are for Mexico.
What it is
A government bond where both the interest and the sum repaid at the end are adjusted for a price index. Instead of a fixed number of pounds or dollars, you are promised a fixed amount of buying power plus a small real rate on top.
That makes it the one instrument that answers the question savers actually care about: will this money still buy the same things in ten years? A normal bond cannot promise that; an inflation-linked one can, if held to maturity.
Between issue and maturity it is still a bond, so its price moves with real interest rates. In 2022, when real rates jumped, long-dated linkers fell by a third or more, which surprised people who thought inflation protection meant no risk.
How it works
- The bond's face value is scaled by an inflation index each period, and the coupon is a small percentage of that scaled value.
- When prices rise, both the interest payments and the eventual repayment rise with them.
- The real rate you lock in is set by the price you pay; it can be positive, zero or negative.
- At maturity you receive the inflation-adjusted face value, often with a floor at the original amount.
The honest pros and cons
For
- The only mainstream instrument that directly protects buying power.
- Backed by the same government promise as ordinary bonds.
- Useful for money earmarked for a distant, real-world cost such as retirement spending.
Against
- Price falls can be severe when real interest rates rise, especially for long maturities.
- The real rate on offer is sometimes tiny or negative, meaning you pay for the protection.
- The tax on the inflation uplift can be awkward in some countries.
- Which price index is used matters; it may not match your own cost of living.
Getting it in Mexico
Udibonos available
Wherever you are
- Check the real yield on offer; below zero, you are paying for insurance and should know it.
- Match the maturity to when you need the money, because early sale reintroduces price risk.
- Buy directly from the treasury where available, or through a fund that holds a spread of maturities.
Try it
Go deeper
Also called
TIPS, index-linked gilts, I bonds, Tesouro IPCA+, Udibonos, linkers
Often confused with
- Government bond: A loan to a government that pays interest and returns your money on a set date, called its maturity.
- Savings account: Money kept at a bank that pays interest and can be withdrawn at any time.