Downgrades, e.g

• Changes a grade
• Gives another star to, perhaps
• Awards another star to, perhaps
• Gives a new value to
• Downgrades, e.g.
• Considers bond values again
• Changes at Standard & Poor's, say
• Alters an assessment

Wiktionary Word definitions in Wiktionary
vb. (en-third-person singular of: rerate )