A rating downgrade happens when certain material facts about the financial position of the issuer or the bond deteriorate. The rating agency will then move the rating down to reflect the new position of the issuer. Credit rating downgrades may make a previously high-grade bond become high-yield. This event may bring in more money from investors looking at high-yield investments. Investors who specifically want lower-credit quality exposure may choose to enter the bond. A downgrade usually makes it difficult to exit the bond without selling it at lower prices.