How bonds work and what drives their prices
When you buy a bond at issue and hold it to maturity, you generally receive the stated coupon payments and the face value back, assuming the issuer does not default. If you buy or sell a bond before maturity, the price depends on market conditions. The key relationship to understand is that bond prices usually fall when market interest rates rise, and rise when rates fall. Longer-dated bonds are typically more sensitive to rate changes, a sensitivity often measured by duration. Credit quality matters too: bonds from issuers with weaker finances usually offer higher yields to compensate for higher default risk.
- Interest rate risk: prices generally move inversely to market interest rates.
- Credit risk: the issuer may fail to pay coupons or repay principal.
- Inflation risk: fixed coupons lose purchasing power when inflation rises.
- Duration indicates how sensitive a bond or bond fund is to rate changes.

