Diversification and bond portfolio management often go hand in hand. There are two reasons for this: firstly, because the multitude and variety of asset classes underlying the bond market means there is a wide gap between the asset considered to be the safest in the world (Treasury notes) and the debt of financially fragile companies (high-yield bonds). Secondly, because at the “lower” level, i.e. within the indices, these asset classes contain hundreds of different securities.