The addition of the individual contributions to expected excess return in Our study yields an expected 1-year excess return of 88.2 bp for A-rated corporate bonds with a maturity of 5-years. This is significantly below the initial spread of 100 bps. The difference reflects the fact that a downgrade is more probable for A-rated corporate bonds than an upgrade, and that the associated spread changes are not symmetric. The magnitude of spread widenings due to downgrades is usually much higher than the spread tightening after rating upgrades. It is interesting to note that among investment grade bonds the ratio of upgrades to downgrades is most favorable for Baa-rated bonds. However, in the case of a downgrade these bonds often suffer massive price declines, because they fall below investment grade levels.