overvaluation vs rating

overvaluation and rating both are nouns.

Word	Noun	Adjective	Verb	Adverb
overvaluation	Yes	No	No	No
rating	Yes	No	No	No

As nouns, rating is a hypernym of overvaluation; that is, rating is a word with a broader meaning than overvaluation:

Other hypernyms of overvaluation include evaluation, valuation.

overvaluation (noun)	rating (noun)
too high a value or price assigned to something	act of ascertaining or fixing the value or worth of
an appraisal that is too high	an appraisal of the value of something
	standing or position on a scale
	rank in a military organization