Interpreting Government Bond Yields as Annualized Yield to Maturity

Summary

The document explains that a quoted government bond yield, such as a ten-year yield of two percent, is generally an annualized yield to maturity rather than a single return earned only at the end of the holding period. Under the yield-to-maturity calculation, an investor buys the bond at its current full price, holds it until maturity, and assumes coupon payments can be reinvested at that same yield. Under those assumptions, the quoted rate describes an annualized return over the bond’s life.

The key limitation is that future reinvestment rates are unknown, so the assumed rate on coupon reinvestment cannot be guaranteed. The stated yield is therefore a convenient summary measure and estimate, not a promise of the realized return. The document gives a conceptual definition but no bond-price calculation or discussion of other influences on realized returns, such as a sale before maturity or changes in market yields.

Key ideas

• Yield to maturity is an annualized rate based on the bond’s current full price and cash flows through maturity.
• The calculation assumes coupon payments can be reinvested at the yield-to-maturity rate.
• A quoted yield does not guarantee the investor will realize that rate because future reinvestment rates are unknown.
• The explanation describes a hold-to-maturity assumption and does not address returns from selling earlier.

Tags

# Are government bond yields usually expressed as yield to maturity (YTM) or annual yield?


# Are government bond yields usually expressed as yield to maturity (YTM) or annual yield?












If US 10yr = 2%, does it mean if I hold the bond until maturity/for next 10 years the yield is 2% or I get an annual return of 2% for 10 years?

For example the yields in the link:

https://www.investing.com/rates-bonds/world-government-bonds

## Answer by Dom (score 2)

https://quant.stackexchange.com/a/60971

The yield to maturity of a bond $y$ is the constant annualised yield that you would receive if you buy the bond today at its current full price $P$ and hold it until maturity with the additional assumption that all of the coupon payments received over the life of the bond can be reinvested from the time received until maturity at this yield.

If it is 2% and $T=10$ years, then it implies that you get a 2% return every year for 10 years.

However, as we cannot know the future reinvestment yields today, there is no certainty that the yield-to-maturity $y$ will actually be realised and so we cannot know the exact yield to maturity in advance. Just see it as a best quick and dirty estimate.

Shown in full with attribution under the source's licence. Licence: CC BY-SA 4.0 (Stack Exchange)

This summary was written by Stratmill's research agent from the original; it is not a copy of the source.