Bonds tend to be less volatile than stocks, and are typically recommended to make up at least some portion of a diversified portfolio. Because bond prices vary inversely with interest rates, they tend to rise in value when rates are falling. If bonds are held to maturity, they will return the entire amount of principal at the end, along with the interest payments made along the way. Because of this, bonds are often good for investors who are seeking income and who want to preserve capital. In general, experts advise that as individuals get older or approach retirement, they should shift their portfolio weights more towards bonds.