undervaluation vs rating

undervaluation and rating both are nouns.

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

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

Other hypernyms of undervaluation include evaluation, valuation.

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